CVE-2026-93569
Io.netty/netty-codec-http2: http/1 absolute-form host mismatch is translated to http/2 :authority, overriding the request-target authority
Description
A flaw was found in Netty. A remote unauthenticated attacker can exploit a vulnerability in Netty's HTTP/1 to HTTP/2 conversion process. When an HTTP/1 request includes both an absolute-form request-target and a conflicting Host header, Netty incorrectly prioritizes the Host header for the HTTP/2 :authority field, discarding the original request-target authority. This inconsistency can allow an attacker to bypass security controls in Netty-based proxies or gateways, potentially leading to unauthorized access, cache poisoning, or misrouting of requests.
INFO
Published Date :
Sept. 18, 2026, 3:17 p.m.
Last Modified :
Sept. 22, 2026, 7:16 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
Affected Products
The following products are affected by CVE-2026-93569
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.
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | HIGH | 53f830b8-0a3f-465b-8143-3b8a9948e749 | ||||
| CVSS 3.1 | HIGH | MITRE-CVE | ||||
| CVSS 3.1 | HIGH | [email protected] |
Solution
- Update HTTP/2 server configuration.
- Enforce Host header validation.
- Apply security patches for HTTP/2 implementation.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-93569.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-93569 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-2026-93569
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).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-93569 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-93569 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.
-
CVE Modified by [email protected]
Sep. 22, 2026
Action Type Old Value New Value Added Reference https://access.redhat.com/errata/RHSA-2026:69440 Added Reference https://access.redhat.com/errata/RHSA-2026:70257 -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Sep. 22, 2026
Action Type Old Value New Value Added SSVC {'id': 'CVE-2026-93569', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'yes'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-09-22T14:36:45.463553Z'} -
CVE Modified by [email protected]
Sep. 21, 2026
Action Type Old Value New Value Added Affected Affected value modified. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/93xxx/CVE-2026-93569.json">CVE-2026-93569</a> Added Reference https://access.redhat.com/errata/RHSA-2026:69470 -
CVE Modified by [email protected]
Sep. 18, 2026
Action Type Old Value New Value Changed Description HTTP/1 absolute-form Host mismatch is translated to HTTP/2 :authority, overriding the request-target authority A flaw was found in Netty. A remote unauthenticated attacker can exploit a vulnerability in Netty's HTTP/1 to HTTP/2 conversion process. When an HTTP/1 request includes both an absolute-form request-target and a conflicting Host header, Netty incorrectly prioritizes the Host header for the HTTP/2 :authority field, discarding the original request-target authority. This inconsistency can allow an attacker to bypass security controls in Netty-based proxies or gateways, potentially leading to unauthorized access, cache poisoning, or misrouting of requests. -
CVE Modified by [email protected]
Sep. 18, 2026
Action Type Old Value New Value Added Affected Affected value modified. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/93xxx/CVE-2026-93569.json">CVE-2026-93569</a> -
New CVE Received by [email protected]
Sep. 18, 2026
Action Type Old Value New Value Added Description HTTP/1 absolute-form Host mismatch is translated to HTTP/2 :authority, overriding the request-target authority Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:N Added CWE CWE-444 Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/93xxx/CVE-2026-93569.json">CVE-2026-93569</a> Added Reference https://access.redhat.com/security/cve/CVE-2026-93569 Added Reference https://bugzilla.redhat.com/show_bug.cgi?id=2536962