CVE-2026-55149 (GCVE-0-2026-55149)

Vulnerability from cvelistv5 – Published: 2026-09-15 16:30 – Updated: 2026-09-17 16:08
VLAI
Title
Vouch Proxy: Unbounded Multipart Cookie Allocation DoS
Summary
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.
SSVC
Exploitation: poc Automatable: yes Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-09-17 16:05 UTC
CWE
  • CWE-789 - Memory Allocation with Excessive Size Value
Assigner
GitHub_M CNA under the mitre root
CNA scorecard C 72/100 over 7982 records in the last 180 days details
Impacted products
Vendor Product Version CPE status
vouch vouch-proxy Affected: < 0.48.0
guessed Create a notification for this product.
Show details on NVD website

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