What’s Vulnerable › Vulnerabilities

CVE-2026-118681: go-chi chi before 5.5.0 Authentication Bypass via SupressNotFound Middleware

• Severity: low (CVSS 3.7 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.2% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-10-28 · updated 2026-10-28
• Weakness: CWE-288

Description

go-chi chi before 5.5.0 contains an authentication bypass in middleware.SupressNotFound, which calls Match with the live routing context and leaves a mounted router's parameter and child suffix in place for dispatch against the outer router. Unauthenticated attackers can request a mounted path whose suffix matches an outer public route, skipping the mounted authentication middleware and retrieving tenant-scoped data when that outer handler trusts the retained mount parameter.

Affected products

• go-chi chi: before 5.5.0 — fixed in 5.5.0

How to fix

Upgrade to a fixed version: go-chi chi 5.5.0. Check the vendor advisory for mitigations.

References

• https://github.com/go-chi/chi/security/advisories/GHSA-rqrp-8cg2-5958
• https://www.vulncheck.com/advisories/go-chi-chi-before-5.5.0-authentication-bypass-via-supressnotfound-middleware

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