SEPTEMBER 17, 2026
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Case File

CVE-2026-55149

HIGH · CVSS 7.5 EPSS 0.40% Public Exploit

Source: NVD + CISA KEV + EPSS · Published 2026-09-15 · Last synced 2026-09-17

CyberRota Analysis

AI-Generated

The vulnerability affects Vouch Proxy, an SSO and OAuth/OIDC solution for Nginx, where an attacker can exploit the parsing of multipart cookie names to trigger a denial-of-service condition by causing excessive memory allocation. This can lead to the authentication proxy crashing, impacting service availability without requiring valid user credentials. Organizations using Vouch Proxy versions prior to 0.48.0 should prioritize upgrading to mitigate this high-severity risk.

Public Exploit Signal

A public exploit, PoC, GitHub repository or Metasploit reference was detected for this CVE.

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CVE
CVE-2026-55149
Severity
HIGH
CVSS
7.5
EPSS
0.40%
Nginx

Original NVD Description

Vouch Proxy is an SSO and OAuth/OIDC login solution for Nginx using the auth_request module. Prior to 0.48.0, Cookie in pkg/cookie/cookie.go parses the total part count from an attacker-controlled multipart cookie name and passes the value to make([]string, numParts) without checking that the value is positive or reasonably bounded. Requests to /validate and /_external-auth-:id reach JWTCacheHandler in pkg/jwtmanager/jwtcache.go, FindJWT in pkg/jwtmanager/jwtmanager.go, and the vulnerable cookie reassembly before JWT validation, so no account or valid session is required. A cookie name such as VouchCookie_1of10000000000 causes an attempted slice allocation of roughly 160 GB and a fatal Go runtime out-of-memory condition, allowing one request to crash the authentication proxy and repeated requests to sustain unavailability. This vulnerability is fixed in 0.48.0.