Summary
There is a potential vulnerability in Traefik due to its dependency on an affected version of gRPC-Go (CVE-2026-33186).
A remote, unauthenticated attacker can send gRPC requests with a malformed HTTP/2 :path pseudo-header omitting the mandatory leading slash (e.g., Service/Method instead of /Service/Method). While the server routes such requests correctly, path-based authorization interceptors evaluate the raw non-canonical path and fail to match "deny" rules, allowing the request to bypass the policy entirely if a fallback "allow" rule is present.
For more information
If there are any questions or comments about this advisory, please open an issue.
Original DescriptionThis CVE hits traefik until Version 3.6.11 and 2.11.41.
gRPC-Go has an authorization bypass via missing leading slash in :path
Details
As described in https://github.com/advisories/GHSA-p77j-4mvh-x3m3
PoC
Update library version in
https://github.com/traefik/traefik/blob/67c64ed9b25fbb90f1086977a62827133a7aa01b/go.mod#L108
Impact
Is described in https://github.com/advisories/GHSA-p77j-4mvh-x3m3
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
Remediation advice
Frequently Asked Questions
- What is GHSA-46WH-3698-F2CX? GHSA-46WH-3698-F2CX is a high-severity security vulnerability in github.com/traefik/traefik/v2 (go), affecting versions < 2.11.42. It is fixed in 2.11.42, 3.6.12, 3.7.0-ea.3.
- Which packages are affected by GHSA-46WH-3698-F2CX?
github.com/traefik/traefik/v2(go) (versions < 2.11.42)github.com/traefik/traefik/v3(go) (versions >= 3.0.0-beta3, < 3.6.12)
- Is there a fix for GHSA-46WH-3698-F2CX? Yes. GHSA-46WH-3698-F2CX is fixed in 2.11.42, 3.6.12, 3.7.0-ea.3. Upgrade to this version or later.
- Is GHSA-46WH-3698-F2CX exploitable, and should I be worried? Whether GHSA-46WH-3698-F2CX is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether GHSA-46WH-3698-F2CX is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix GHSA-46WH-3698-F2CX?
- Upgrade
github.com/traefik/traefik/v2to 2.11.42 or later - Upgrade
github.com/traefik/traefik/v3to 3.6.12 or later - Upgrade
github.com/traefik/traefik/v3to 3.7.0-ea.3 or later
- Upgrade