9.3
CRITICAL CVSS 4.0
CVE-2026-58172
Ocelot - IP Allow/Block List Bypass for WebSocket Upgrade Requests
Description

Ocelot through 24.1.0, fixed in commit f156fd4, contains a security control bypass vulnerability that allows denied clients to circumvent IP-based access restrictions by sending WebSocket upgrade requests. The WebSocket upgrade pipeline branch configured via MapWhen in OcelotPipelineExtensions.cs omits SecurityMiddleware, causing requests from blocked IP addresses to be proxied to downstream services without enforcement of the configured allow/block list.

INFO

Published Date :

June 30, 2026, 5:16 p.m.

Last Modified :

July 14, 2026, 10:17 p.m.

Remotely Exploit :

Yes !
Affected Products

The following products are affected by CVE-2026-58172 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.

No affected product recoded yet

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 CRITICAL 83251b91-4cc7-4094-a5c7-464a1b83ea10
CVSS 3.1 CRITICAL [email protected]
CVSS 4.0 CRITICAL 83251b91-4cc7-4094-a5c7-464a1b83ea10
CVSS 4.0 CRITICAL [email protected]
Solution
Update Ocelot to bypass IP restrictions for WebSocket upgrade requests.
  • Update Ocelot to version that includes commit f156fd4.
  • Ensure SecurityMiddleware is included in the pipeline.
  • Review WebSocket upgrade request handling.
  • Apply IP allow/block list rules correctly.
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-2026-58172 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-2026-58172 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-2026-58172 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-58172 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]

    Jul. 14, 2026

    Action Type Old Value New Value
    Changed Affected [{'repo': 'https://github.com/ThreeMammals/Ocelot', 'vendor': 'ThreeMammals', 'product': 'Ocelot', 'versions': [{'status': 'affected', 'version': '0', 'versionType': 'semver', 'lessThanOrEqual': '24.1.0'}, {'status': 'unaffected', 'version': 'f156fd4017ca25025fffdad8ec56c1d657dfb402', 'versionType': 'git'}], 'defaultStatus': 'unaffected'}] [{'repo': 'https://github.com/ThreeMammals/Ocelot', 'vendor': 'ThreeMammals', 'product': 'Ocelot', 'versions': [{'status': 'affected', 'version': '0', 'versionType': 'semver', 'lessThanOrEqual': '24.1.0'}, {'status': 'unaffected', 'version': 'f156fd4017ca25025fffdad8ec56c1d657dfb402', 'versionType': 'git'}], 'packageURL': 'pkg:github/ThreeMammals/Ocelot', 'defaultStatus': 'unaffected'}]
  • CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0

    Jul. 02, 2026

    Action Type Old Value New Value
    Changed SSVC {'id': 'CVE-2026-58172', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'poc'}, {'automatable': 'yes'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-07-01T00:00:00+00:00'} {'id': 'CVE-2026-58172', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'poc'}, {'automatable': 'yes'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-07-02T03:56:10.595991Z'}
  • CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0

    Jul. 02, 2026

    Action Type Old Value New Value
    Changed SSVC {'id': 'CVE-2026-58172', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'poc'}, {'automatable': 'yes'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-07-01T15:03:30.326054Z'} {'id': 'CVE-2026-58172', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'poc'}, {'automatable': 'yes'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-07-01T00:00:00+00:00'}
  • CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0

    Jul. 01, 2026

    Action Type Old Value New Value
    Added SSVC {'id': 'CVE-2026-58172', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'poc'}, {'automatable': 'yes'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-07-01T15:03:30.326054Z'}
  • New CVE Received by [email protected]

    Jun. 30, 2026

    Action Type Old Value New Value
    Added Affected [{'repo': 'https://github.com/ThreeMammals/Ocelot', 'vendor': 'ThreeMammals', 'product': 'Ocelot', 'versions': [{'status': 'affected', 'version': '0', 'versionType': 'semver', 'lessThanOrEqual': '24.1.0'}, {'status': 'unaffected', 'version': 'f156fd4017ca25025fffdad8ec56c1d657dfb402', 'versionType': 'git'}], 'defaultStatus': 'unaffected'}]
    Added Description Ocelot through 24.1.0, fixed in commit f156fd4, contains a security control bypass vulnerability that allows denied clients to circumvent IP-based access restrictions by sending WebSocket upgrade requests. The WebSocket upgrade pipeline branch configured via MapWhen in OcelotPipelineExtensions.cs omits SecurityMiddleware, causing requests from blocked IP addresses to be proxied to downstream services without enforcement of the configured allow/block list.
    Added CVSS V4.0 AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/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:L/PR:N/UI:N/S:U/C:H/I:H/A:N
    Added CWE CWE-288
    Added Reference https://github.com/ThreeMammals/Ocelot/commit/f156fd4017ca25025fffdad8ec56c1d657dfb402
    Added Reference https://github.com/ThreeMammals/Ocelot/issues/2403
    Added Reference https://github.com/ThreeMammals/Ocelot/pull/2406
    Added Reference https://www.vulncheck.com/advisories/ocelot-ip-allow-block-list-bypass-for-websocket-upgrade-requests
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.