9.2
CRITICAL CVSS 4.0
CVE-2026-9256
NGINX ngx_http_rewrite_module vulnerability
Description

NGINX Plus and NGINX Open Source have a vulnerability in the ngx_http_rewrite_module module. This vulnerability exists when a rewrite directive uses a regex pattern with distinct, overlapping Perl-Compatible Regular Expression (PCRE) captures (for example, ^/((.*))$) and a replacement string that references multiple such captures (for example, $1$2) in a redirect or arguments context. An unauthenticated attacker along with conditions beyond their control can exploit this vulnerability by sending crafted HTTP requests. This may cause a heap buffer overflow in the NGINX worker process leading to a restart. Additionally, attackers can execute code on systems with Address Space Layout Randomization (ASLR) disabled or when the attacker can bypass ASLR. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.

INFO

Published Date :

May 22, 2026, 3:16 p.m.

Last Modified :

Aug. 11, 2026, 2:48 p.m.

Remotely Exploit :

Yes !
Affected Products

The following products are affected by CVE-2026-9256 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 F5 nginx_instance_manager
2 F5 nginx_ingress_controller
3 F5 nginx_plus
4 F5 nginx_open_source
5 F5 nginx_gateway_fabric
6 F5 dos
7 F5 waf
1 Redhat enterprise_linux
2 Redhat update_infrastructure
3 Redhat discovery
4 Redhat hardened_images
1 Debian debian_linux
CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 134c704f-9b21-4f2e-91b3-4a467353bcc0
CVSS 3.1 HIGH 9dacffd4-cb11-413f-8451-fbbfd4ddc0ab
CVSS 3.1 HIGH MITRE-CVE
CVSS 3.1 HIGH [email protected]
CVSS 3.1 HIGH 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
CVSS 4.0 CRITICAL 9dacffd4-cb11-413f-8451-fbbfd4ddc0ab
CVSS 4.0 CRITICAL [email protected]
Solution
Update NGINX to a version that addresses the rewrite module heap buffer overflow vulnerability.
  • Update NGINX Plus to the latest version.
  • Update NGINX Open Source to the latest version.
  • Review and fix rewrite rules with overlapping PCRE captures.
  • Disable ASLR if possible and not already enabled.
Public PoC/Exploit Available at Github

CVE-2026-9256 has a 16 public PoC/Exploit available at Github. Go to the Public Exploits tab to see the list.

References to Advisories, Solutions, and Tools
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-9256 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-9256 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

None

Dockerfile Python Shell

Updated: 1 month, 3 weeks ago
2 stars 1 fork 1 watcher
Born at : June 20, 2026, 3:39 a.m. This repo has been linked 2 different CVEs too.

None

Python

Updated: 1 month, 2 weeks ago
1 stars 0 fork 0 watcher
Born at : June 19, 2026, 6:51 a.m. This repo has been linked 1 different CVEs too.

Nginx RCE chain PoC with CVE-2026-9256 and CVE-2026-42945

Python Shell

Updated: 2 months ago
2 stars 1 fork 1 watcher
Born at : June 5, 2026, 3:21 p.m. This repo has been linked 2 different CVEs too.

CVE-2026-9256 Nginx heap buffer overflow POC

Python

Updated: 2 months, 1 week ago
0 stars 0 fork 0 watcher
Born at : June 3, 2026, 2:17 a.m. This repo has been linked 1 different CVEs too.

Echo assignment - shalev lavyuod

Makefile Shell Dockerfile Python

Updated: 2 months, 1 week ago
0 stars 0 fork 0 watcher
Born at : June 1, 2026, 5:05 p.m. This repo has been linked 2 different CVEs too.

Local AI-augmented offensive-security scanner: attack surface, CVE+exploitability, client-side intel, lab-mode verification, exploit-chain correlation. Authorization-gated.

Python JavaScript HTML CSS Shell Dockerfile

Updated: 3 weeks, 2 days ago
0 stars 0 fork 0 watcher
Born at : May 31, 2026, 7:21 p.m. This repo has been linked 2 different CVEs too.

None

Dockerfile Shell Makefile Python

Updated: 2 months, 1 week ago
0 stars 0 fork 0 watcher
Born at : May 29, 2026, 6:26 p.m. This repo has been linked 40 different CVEs too.

Community-maintained fork of kubernetes/ingress-nginx with NGINX 1.30.2

fork cve docker helm ingress ingress-controller kubernetes kubernetes-ingress load-balancer nginx nginx130 reverse-proxy security

Lua Makefile Shell Go Template Mustache Go Python Dockerfile HTML JavaScript

Updated: 1 month, 1 week ago
1 stars 0 fork 0 watcher
Born at : May 28, 2026, 4:05 p.m. This repo has been linked 10 different CVEs too.

poc

Python

Updated: 1 month, 2 weeks ago
1 stars 0 fork 0 watcher
Born at : May 28, 2026, 6:56 a.m. This repo has been linked 2 different CVEs too.

cPanel/WHM CVE auditor & patcher — May 2026 batch, zero dependencies.

Shell

Updated: 2 months, 2 weeks ago
2 stars 0 fork 0 watcher
Born at : May 24, 2026, 9:31 a.m. This repo has been linked 8 different CVEs too.

Tracking the nginx CVE-2026-9256 rewrite-module heap overflow

nginx security

Shell Makefile Nix CSS HTML

Updated: 2 months, 2 weeks ago
0 stars 0 fork 0 watcher
Born at : May 24, 2026, 2:43 a.m. This repo has been linked 1 different CVEs too.

None

Updated: 1 month, 3 weeks ago
1 stars 0 fork 0 watcher
Born at : April 3, 2026, 10:56 a.m. This repo has been linked 1 different CVEs too.

WNMP One‑Click Stack | WebDAV · Nginx · PHP · MariaDB · Kernel Tuning

Shell

Updated: 3 weeks, 6 days ago
26 stars 4 fork 4 watcher
Born at : Dec. 7, 2025, 11:39 p.m. This repo has been linked 13 different CVEs too.

一个 CVE 漏洞预警知识库,无 exp/poc,部分包含修复方案。A knowledge base of CVE security vulnerability, no PoCs/exploits.

Updated: 3 weeks, 3 days ago
175 stars 25 fork 25 watcher
Born at : Jan. 5, 2023, 2:19 a.m. This repo has been linked 279 different CVEs too.

SecDB - Security Feeds

cve security-feeds vulnerability

Updated: 3 weeks, 5 days ago
0 stars 0 fork 0 watcher
Born at : July 1, 2022, 8:37 p.m. This repo has been linked 133 different CVEs too.

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-9256 vulnerability anywhere in the article.

  • The Cyber Express
CVE-2026-42533 Exposes Critical Pre-Auth nginx RCE Flaw

A newly disclosed security flaw, CVE-2026-42533, has revealed a critical Pre-Auth nginx vulnerability that could allow attackers to achieve reliable RCE (remote code execution) without authentication. ... Read more

Published Date: Jul 20, 2026 (3 weeks, 3 days ago)
  • The Hacker News
Critical NGINX Vulnerability Can Crash Workers and May Allow Remote Code Execution

F5 has shipped fixes for a critical nginx flaw that lets a remote, unauthenticated attacker trigger a heap buffer overflow in the worker process with crafted HTTP requests. CVE-2026-42533 was patched ... Read more

Published Date: Jul 19, 2026 (3 weeks, 4 days ago)
  • CybersecurityNews
Nginx-poolslip Vulnerability Enables DoS and Code Execution Attacks — Patch Now!

A newly disclosed flaw in one of the world’s most widely deployed web servers is forcing administrators into another emergency patch cycle. Tracked as CVE-2026-9256 and publicly nicknamed nginx-poolsl ... Read more

Published Date: May 23, 2026 (2 months, 3 weeks ago)

The following table lists the changes that have been made to the CVE-2026-9256 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • Modified Analysis by [email protected]

    Aug. 11, 2026

    Action Type Old Value New Value
    Added CPE Configuration OR *cpe:2.3:a:f5:nginx_gateway_fabric:*:*:*:*:*:*:*:* versions from (including) 1.3.0 up to (including) 1.6.2 *cpe:2.3:a:f5:dos:*:*:*:*:*:nginx:*:* versions from (including) 4.3.0 up to (including) 4.7.0 *cpe:2.3:a:f5:dos:4.9.0:*:*:*:*:nginx:*:* *cpe:2.3:a:f5:waf:*:*:*:*:*:nginx:*:* versions from (including) 4.10.0 up to (including) 4.16.0 *cpe:2.3:a:f5:waf:*:*:*:*:*:nginx:*:* versions from (including) 5.2.0 up to (including) 5.8.0 *cpe:2.3:a:f5:nginx_ingress_controller:*:*:*:*:continuous_releases:*:*:* versions from (including) 3.5.0 up to (including) 3.7.2 *cpe:2.3:a:f5:nginx_instance_manager:*:*:*:*:*:*:*:* versions from (including) 2.17.0 up to (excluding) 2.22.1 *cpe:2.3:a:f5:waf:*:*:*:*:*:nginx:*:* versions from (including) 5.9.0 up to (including) 5.13.0 *cpe:2.3:a:f5:nginx_gateway_fabric:*:*:*:*:*:*:*:* versions from (including) 2.0.0 up to (excluding) 2.6.2 *cpe:2.3:a:f5:nginx_ingress_controller:*:*:*:*:continuous_releases:*:*:* versions from (including) 4.0.0 up to (including) 4.0.1 *cpe:2.3:a:f5:nginx_ingress_controller:*:*:*:*:continuous_releases:*:*:* versions from (including) 5.0.0 up to (excluding) 5.4.3
    Added CPE Configuration OR *cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:* *cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:*:*:*:* *cpe:2.3:a:redhat:discovery:-:*:*:*:*:*:*:* *cpe:2.3:o:redhat:enterprise_linux:9.0:*:*:*:*:*:*:* *cpe:2.3:o:redhat:enterprise_linux:10.0:*:*:*:*:*:*:* *cpe:2.3:a:redhat:hardened_images:-:*:*:*:*:*:*:* *cpe:2.3:a:redhat:update_infrastructure:*:*:*:*:*:*:*:* versions from (including) 5.0 up to (excluding) 5.2
    Changed CPE Configuration OR *cpe:2.3:a:f5:nginx_plus:*:*:*:*:*:*:*:* versions from (including) r32 up to (including) r36 *cpe:2.3:a:f5:nginx_open_source:*:*:*:*:*:*:*:* versions from (including) 0.1.17 up to (including) 0.9.7 *cpe:2.3:a:f5:nginx_open_source:*:*:*:*:*:*:*:* versions from (including) 1.0.0 up to (including) 1.30.1 *cpe:2.3:a:f5:nginx_open_source:1.31.0:*:*:*:*:*:*:* *cpe:2.3:a:f5:nginx_plus:*:*:*:*:*:*:*:* versions from (including) 37.0.0 up to (excluding) 37.0.1.1 OR *cpe:2.3:a:f5:nginx_open_source:*:*:*:*:*:*:*:* versions from (including) 0.1.17 up to (including) 0.9.7 *cpe:2.3:a:f5:nginx_open_source:1.31.0:*:*:*:*:*:*:* *cpe:2.3:a:f5:nginx_plus:*:*:*:*:continuous_releases:*:*:* versions from (including) r33 up to (excluding) r36 *cpe:2.3:a:f5:nginx_plus:37.0.0.1:*:*:*:long-term_support:*:*:* *cpe:2.3:a:f5:nginx_plus:r32:-:*:*:continuous_releases:*:*:* *cpe:2.3:a:f5:nginx_plus:r32:p1:*:*:continuous_releases:*:*:* *cpe:2.3:a:f5:nginx_plus:r32:p2:*:*:continuous_releases:*:*:* *cpe:2.3:a:f5:nginx_plus:r32:p3:*:*:continuous_releases:*:*:* *cpe:2.3:a:f5:nginx_plus:r32:p4:*:*:continuous_releases:*:*:* *cpe:2.3:a:f5:nginx_plus:r32:p5:*:*:continuous_releases:*:*:* *cpe:2.3:a:f5:nginx_plus:r32:p6:*:*:continuous_releases:*:*:* *cpe:2.3:a:f5:nginx_plus:r36:-:*:*:continuous_releases:*:*:* *cpe:2.3:a:f5:nginx_plus:r36:p1:*:*:continuous_releases:*:*:* *cpe:2.3:a:f5:nginx_plus:r36:p2:*:*:continuous_releases:*:*:* *cpe:2.3:a:f5:nginx_plus:r36:p3:*:*:continuous_releases:*:*:* *cpe:2.3:a:f5:nginx_plus:r36:p4:*:*:continuous_releases:*:*:* *cpe:2.3:a:f5:nginx_open_source:*:*:*:*:*:*:*:* versions from (including) 1.0.0 up to (excluding) 1.30.2
    Changed Reference Type CVE: http://www.openwall.com/lists/oss-security/2026/05/22/14 Types: Mailing List, Third Party Advisory CVE: http://www.openwall.com/lists/oss-security/2026/05/22/14 Types: Mailing List
    Added Reference Type CVE: https://lists.debian.org/debian-lts-announce/2026/06/msg00023.html Types: Mailing List, Third Party Advisory
    Added Reference Type redhat-SADP: https://access.redhat.com/errata/RHSA-2026:20351 Types: Third Party Advisory
    Added Reference Type redhat-SADP: https://access.redhat.com/errata/RHSA-2026:28212 Types: Third Party Advisory
    Added Reference Type redhat-SADP: https://access.redhat.com/errata/RHSA-2026:28921 Types: Third Party Advisory
    Added Reference Type redhat-SADP: https://access.redhat.com/errata/RHSA-2026:28973 Types: Third Party Advisory
    Added Reference Type redhat-SADP: https://access.redhat.com/errata/RHSA-2026:29151 Types: Third Party Advisory
    Added Reference Type redhat-SADP: https://access.redhat.com/errata/RHSA-2026:29874 Types: Third Party Advisory
    Added Reference Type redhat-SADP: https://access.redhat.com/errata/RHSA-2026:33313 Types: Third Party Advisory
    Added Reference Type redhat-SADP: https://access.redhat.com/errata/RHSA-2026:44481 Types: Third Party Advisory
    Added Reference Type redhat-SADP: https://access.redhat.com/security/cve/CVE-2026-9256 Types: Third Party Advisory
    Added Reference Type redhat-SADP: https://bugzilla.redhat.com/show_bug.cgi?id=2480746 Types: Issue Tracking, Third Party Advisory
    Added Reference Type redhat-SADP: https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-9256.json Types: Third Party Advisory
  • CVE Modified by 0b0ca135-0b70-47e7-9f44-1890c2a1c46c

    Jul. 24, 2026

    Action Type Old Value New Value
    Added Reference https://access.redhat.com/errata/RHSA-2026:44481
    Changed Affected [{'cpes': ['cpe:/o:redhat:enterprise_linux:10.2'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux 10', 'versions': [{'status': 'unaffected', 'version': '2:1.26.3-6.el10_2.4', 'lessThan': '*', 'versionType': 'rpm'}], 'packageName': 'nginx', 'collectionURL': 'https://access.redhat.com/downloads/content/package-browser/', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:enterprise_linux:8'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux 8', 'versions': [{'status': 'unaffected', 'version': '8100020260611094050.489197e6', 'lessThan': '*', 'versionType': 'rpm'}], 'packageName': 'nginx:1.24', 'collectionURL': 'https://access.redhat.com/downloads/content/package-browser/', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:enterprise_linux:9'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux 9', 'versions': [{'status': 'unaffected', 'version': '9080020260610161820.9', 'lessThan': '*', 'versionType': 'rpm'}], 'packageName': 'nginx:1.24', 'collectionURL': 'https://access.redhat.com/downloads/content/package-browser/', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:enterprise_linux:9'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux 9', 'versions': [{'status': 'unaffected', 'version': '2:1.20.1-28.el9_8.3', 'lessThan': '*', 'versionType': 'rpm'}], 'packageName': 'nginx', 'collectionURL': 'https://access.redhat.com/downloads/content/package-browser/', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:enterprise_linux:9'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux 9', 'versions': [{'status': 'unaffected', 'version': '9080020260609152155.9', 'lessThan': '*', 'versionType': 'rpm'}], 'packageName': 'nginx:1.26', 'collectionURL': 'https://access.redhat.com/downloads/content/package-browser/', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:discovery:2::el9'], 'vendor': 'Red Hat', 'product': 'Red Hat Discovery 2', 'versions': [{'status': 'unaffected', 'version': '1782756541', 'lessThan': '*', 'versionType': 'rpm'}], 'packageName': 'discovery/discovery-ui-rhel9', 'collectionURL': 'https://catalog.redhat.com/software/containers/', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:hummingbird:1'], 'vendor': 'Red Hat', 'product': 'Red Hat Hardened Images', 'versions': [{'status': 'unaffected', 'version': '1.30.2-1.hum1', 'lessThan': '*', 'versionType': 'rpm'}], 'packageName': 'nginx-main', 'collectionURL': 'https://access.redhat.com/downloads/content/package-browser/', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:insights_proxy:1'], 'vendor': 'Red Hat', 'product': 'Red Hat Lightspeed proxy 1', 'packageName': 'insights-proxy/insights-proxy-container-rhel9', 'collectionURL': 'https://access.redhat.com/downloads/content/package-browser/', 'defaultStatus': 'affected'}] [{'cpes': ['cpe:/o:redhat:enterprise_linux:10.2'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux 10', 'versions': [{'status': 'unaffected', 'version': '2:1.26.3-6.el10_2.4', 'lessThan': '*', 'versionType': 'rpm'}], 'packageName': 'nginx', 'collectionURL': 'https://access.redhat.com/downloads/content/package-browser/', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:enterprise_linux:8'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux 8', 'versions': [{'status': 'unaffected', 'version': '8100020260611094050.489197e6', 'lessThan': '*', 'versionType': 'rpm'}], 'packageName': 'nginx:1.24', 'collectionURL': 'https://access.redhat.com/downloads/content/package-browser/', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:enterprise_linux:9'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux 9', 'versions': [{'status': 'unaffected', 'version': '9080020260610161820.9', 'lessThan': '*', 'versionType': 'rpm'}], 'packageName': 'nginx:1.24', 'collectionURL': 'https://access.redhat.com/downloads/content/package-browser/', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:enterprise_linux:9'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux 9', 'versions': [{'status': 'unaffected', 'version': '2:1.20.1-28.el9_8.3', 'lessThan': '*', 'versionType': 'rpm'}], 'packageName': 'nginx', 'collectionURL': 'https://access.redhat.com/downloads/content/package-browser/', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:enterprise_linux:9'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux 9', 'versions': [{'status': 'unaffected', 'version': '9080020260609152155.9', 'lessThan': '*', 'versionType': 'rpm'}], 'packageName': 'nginx:1.26', 'collectionURL': 'https://access.redhat.com/downloads/content/package-browser/', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:discovery:2::el9'], 'vendor': 'Red Hat', 'product': 'Red Hat Discovery 2', 'versions': [{'status': 'unaffected', 'version': '1782756541', 'lessThan': '*', 'versionType': 'rpm'}], 'packageName': 'discovery/discovery-ui-rhel9', 'collectionURL': 'https://catalog.redhat.com/software/containers/', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:hummingbird:1'], 'vendor': 'Red Hat', 'product': 'Red Hat Hardened Images', 'versions': [{'status': 'unaffected', 'version': '1.30.2-1.hum1', 'lessThan': '*', 'versionType': 'rpm'}], 'packageName': 'nginx-main', 'collectionURL': 'https://access.redhat.com/downloads/content/package-browser/', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:rhui:5::el9'], 'vendor': 'Red Hat', 'product': 'Red Hat Update Infrastructure 5', 'versions': [{'status': 'unaffected', 'version': '1784794818', 'lessThan': '*', 'versionType': 'rpm'}], 'packageName': 'rhui5/cds-kubernetes-rhel9', 'collectionURL': 'https://catalog.redhat.com/software/containers/', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:rhui:5::el9'], 'vendor': 'Red Hat', 'product': 'Red Hat Update Infrastructure 5', 'versions': [{'status': 'unaffected', 'version': '1784794778', 'lessThan': '*', 'versionType': 'rpm'}], 'packageName': 'rhui5/cds-rhel9', 'collectionURL': 'https://catalog.redhat.com/software/containers/', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:rhui:5::el9'], 'vendor': 'Red Hat', 'product': 'Red Hat Update Infrastructure 5', 'versions': [{'status': 'unaffected', 'version': '1784795076', 'lessThan': '*', 'versionType': 'rpm'}], 'packageName': 'rhui5/rhua-rhel9', 'collectionURL': 'https://catalog.redhat.com/software/containers/', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:insights_proxy:1'], 'vendor': 'Red Hat', 'product': 'Red Hat Lightspeed proxy 1', 'packageName': 'insights-proxy/insights-proxy-container-rhel9', 'collectionURL': 'https://access.redhat.com/downloads/content/package-browser/', 'defaultStatus': 'affected'}]
  • CVE Translated by [email protected]

    Jul. 23, 2026

    Action Type Old Value New Value
    Added Translation Title: NGINX Plus y NGINX Open Source de F5, Description: NGINX Plus y NGINX Open Source tienen una vulnerabilidad en el módulo ngx_http_rewrite_module. Esta vulnerabilidad existe cuando una directiva de reescritura utiliza un patrón de expresión regular (regex) con capturas de expresiones regulares compatibles con Perl (PCRE) distintas y superpuestas (por ejemplo, ^/((.*))$) y una cadena de reemplazo que hace referencia a múltiples de dichas capturas (por ejemplo, $1$2) en un contexto de redirección o de argumentos. Un atacante no autenticado, junto con condiciones fuera de su control, puede explotar esta vulnerabilidad enviando solicitudes HTTP manipuladas. Esto puede causar un desbordamiento de búfer de pila en el proceso de trabajador de NGINX, lo que lleva a un reinicio. Además, los atacantes pueden ejecutar código en sistemas con la aleatorización del espacio de direcciones (ASLR) deshabilitada o cuando el atacante puede eludir ASLR. Nota: Las versiones de software que han alcanzado el fin del soporte técnico (EoTS) no se evalúan.
  • CVE Modified by 0b0ca135-0b70-47e7-9f44-1890c2a1c46c

    Jul. 15, 2026

    Action Type Old Value New Value
    Changed Affected [{'cpes': ['cpe:/o:redhat:enterprise_linux:10.2'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux AppStream (v. 10)', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:enterprise_linux:8::appstream'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux AppStream (v. 8)', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:enterprise_linux:9::appstream'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux AppStream (v. 9)', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/o:redhat:enterprise_linux:10.2'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux CodeReady Linux Builder (v. 10)', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:enterprise_linux:9::crb'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux CodeReady Linux Builder (v. 9)', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:discovery:2::el9'], 'vendor': 'Red Hat', 'product': 'Red Hat Discovery 2', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:hummingbird:1'], 'vendor': 'Red Hat', 'product': 'Red Hat Hardened Images', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:insights_proxy:1'], 'vendor': 'Red Hat', 'product': 'Red Hat Lightspeed proxy 1', 'defaultStatus': 'affected'}] [{'cpes': ['cpe:/o:redhat:enterprise_linux:10.2'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux 10', 'versions': [{'status': 'unaffected', 'version': '2:1.26.3-6.el10_2.4', 'lessThan': '*', 'versionType': 'rpm'}], 'packageName': 'nginx', 'collectionURL': 'https://access.redhat.com/downloads/content/package-browser/', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:enterprise_linux:8'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux 8', 'versions': [{'status': 'unaffected', 'version': '8100020260611094050.489197e6', 'lessThan': '*', 'versionType': 'rpm'}], 'packageName': 'nginx:1.24', 'collectionURL': 'https://access.redhat.com/downloads/content/package-browser/', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:enterprise_linux:9'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux 9', 'versions': [{'status': 'unaffected', 'version': '9080020260610161820.9', 'lessThan': '*', 'versionType': 'rpm'}], 'packageName': 'nginx:1.24', 'collectionURL': 'https://access.redhat.com/downloads/content/package-browser/', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:enterprise_linux:9'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux 9', 'versions': [{'status': 'unaffected', 'version': '2:1.20.1-28.el9_8.3', 'lessThan': '*', 'versionType': 'rpm'}], 'packageName': 'nginx', 'collectionURL': 'https://access.redhat.com/downloads/content/package-browser/', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:enterprise_linux:9'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux 9', 'versions': [{'status': 'unaffected', 'version': '9080020260609152155.9', 'lessThan': '*', 'versionType': 'rpm'}], 'packageName': 'nginx:1.26', 'collectionURL': 'https://access.redhat.com/downloads/content/package-browser/', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:discovery:2::el9'], 'vendor': 'Red Hat', 'product': 'Red Hat Discovery 2', 'versions': [{'status': 'unaffected', 'version': '1782756541', 'lessThan': '*', 'versionType': 'rpm'}], 'packageName': 'discovery/discovery-ui-rhel9', 'collectionURL': 'https://catalog.redhat.com/software/containers/', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:hummingbird:1'], 'vendor': 'Red Hat', 'product': 'Red Hat Hardened Images', 'versions': [{'status': 'unaffected', 'version': '1.30.2-1.hum1', 'lessThan': '*', 'versionType': 'rpm'}], 'packageName': 'nginx-main', 'collectionURL': 'https://access.redhat.com/downloads/content/package-browser/', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:insights_proxy:1'], 'vendor': 'Red Hat', 'product': 'Red Hat Lightspeed proxy 1', 'packageName': 'insights-proxy/insights-proxy-container-rhel9', 'collectionURL': 'https://access.redhat.com/downloads/content/package-browser/', 'defaultStatus': 'affected'}]
  • CVE Modified by 0b0ca135-0b70-47e7-9f44-1890c2a1c46c

    Jun. 30, 2026

    Action Type Old Value New Value
    Added Affected [{'cpes': ['cpe:/o:redhat:enterprise_linux:10.2'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux AppStream (v. 10)', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:enterprise_linux:8::appstream'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux AppStream (v. 8)', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:enterprise_linux:9::appstream'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux AppStream (v. 9)', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/o:redhat:enterprise_linux:10.2'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux CodeReady Linux Builder (v. 10)', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:enterprise_linux:9::crb'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux CodeReady Linux Builder (v. 9)', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:discovery:2::el9'], 'vendor': 'Red Hat', 'product': 'Red Hat Discovery 2', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:hummingbird:1'], 'vendor': 'Red Hat', 'product': 'Red Hat Hardened Images', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:insights_proxy:1'], 'vendor': 'Red Hat', 'product': 'Red Hat Lightspeed proxy 1', 'defaultStatus': 'affected'}]
    Added CVSS V3.1 AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
    Added CWE CWE-122
    Added Reference https://access.redhat.com/errata/RHSA-2026:20351
    Added Reference https://access.redhat.com/errata/RHSA-2026:28212
    Added Reference https://access.redhat.com/errata/RHSA-2026:28921
    Added Reference https://access.redhat.com/errata/RHSA-2026:28973
    Added Reference https://access.redhat.com/errata/RHSA-2026:29151
    Added Reference https://access.redhat.com/errata/RHSA-2026:29874
    Added Reference https://access.redhat.com/errata/RHSA-2026:33313
    Added Reference https://access.redhat.com/security/cve/CVE-2026-9256
    Added Reference https://bugzilla.redhat.com/show_bug.cgi?id=2480746
    Added Reference https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-9256.json
  • CVE Modified by af854a3a-2127-422b-91ae-364da2661108

    Jun. 18, 2026

    Action Type Old Value New Value
    Added Reference https://lists.debian.org/debian-lts-announce/2026/06/msg00023.html
  • CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0

    Jun. 17, 2026

    Action Type Old Value New Value
    Added SSVC {'id': 'CVE-2026-9256', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'no'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-05-22T00:00:00+00:00'}
  • CVE Modified by [email protected]

    Jun. 17, 2026

    Action Type Old Value New Value
    Added Affected [{'vendor': 'F5', 'modules': ['ngx_http_rewrite_module'], 'product': 'NGINX Plus', 'versions': [{'status': 'affected', 'version': '37.0', 'lessThan': '37.0.1.1', 'versionType': 'custom'}, {'status': 'affected', 'version': 'R36', 'lessThan': 'R36 P5', 'versionType': 'custom'}, {'status': 'affected', 'version': 'R32', 'lessThan': 'R32 P7', 'versionType': 'custom'}], 'defaultStatus': 'unknown'}, {'vendor': 'F5', 'modules': ['ngx_http_rewrite_module'], 'product': 'NGINX Open Source', 'versions': [{'status': 'affected', 'version': '1.31.0', 'lessThan': '1.31.1', 'versionType': 'custom'}, {'status': 'affected', 'version': '1.30.0', 'lessThan': '1.30.2', 'versionType': 'custom'}, {'status': 'affected', 'version': '0.1.17', 'versionType': 'custom', 'lessThanOrEqual': '0.9.7'}], 'defaultStatus': 'unaffected'}]
  • Initial Analysis by [email protected]

    Jun. 16, 2026

    Action Type Old Value New Value
    Added CPE Configuration OR *cpe:2.3:a:f5:nginx_plus:*:*:*:*:*:*:*:* versions from (including) r32 up to (including) r36 *cpe:2.3:a:f5:nginx_open_source:*:*:*:*:*:*:*:* versions from (including) 0.1.17 up to (including) 0.9.7 *cpe:2.3:a:f5:nginx_open_source:*:*:*:*:*:*:*:* versions from (including) 1.0.0 up to (including) 1.30.1 *cpe:2.3:a:f5:nginx_open_source:1.31.0:*:*:*:*:*:*:* *cpe:2.3:a:f5:nginx_plus:*:*:*:*:*:*:*:* versions from (including) 37.0.0 up to (excluding) 37.0.1.1
    Added Reference Type CVE: http://www.openwall.com/lists/oss-security/2026/05/22/14 Types: Mailing List, Third Party Advisory
    Added Reference Type F5 Networks: https://my.f5.com/manage/s/article/K000161377 Types: Mitigation, Vendor Advisory
  • CVE Modified by af854a3a-2127-422b-91ae-364da2661108

    May. 23, 2026

    Action Type Old Value New Value
    Added Reference http://www.openwall.com/lists/oss-security/2026/05/22/14
  • New CVE Received by [email protected]

    May. 22, 2026

    Action Type Old Value New Value
    Added Description NGINX Plus and NGINX Open Source have a vulnerability in the ngx_http_rewrite_module module. This vulnerability exists when a rewrite directive uses a regex pattern with distinct, overlapping Perl-Compatible Regular Expression (PCRE) captures (for example, ^/((.*))$) and a replacement string that references multiple such captures (for example, $1$2) in a redirect or arguments context. An unauthenticated attacker along with conditions beyond their control can exploit this vulnerability by sending crafted HTTP requests. This may cause a heap buffer overflow in the NGINX worker process leading to a restart. Additionally, attackers can execute code on systems with Address Space Layout Randomization (ASLR) disabled or when the attacker can bypass ASLR. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.
    Added CVSS V4.0 AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
    Added CVSS V3.1 AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
    Added CWE CWE-122
    Added Reference https://my.f5.com/manage/s/article/K000161377
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.