CVE-2026-65601 — Traefik
Fix: traefik/traefik@26c96a3CVE-2026-65601 is a CWE-863 vulnerability in Traefik. A fix is available for Traefik — see the affected versions and patch details below.
Traefik before 3.7.7 Namespace Confusion via HTTPRoute ExtensionRef
Exploitation Status
No confirmed exploitation observed yet
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-65601.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
Real-World Exposure
TraefikReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.
Description
Traefik versions 3.7.0 through 3.7.6 contain a namespace confusion vulnerability in the Kubernetes Gateway API provider. When resolving HTTPRoute.spec.rules[].backendRefs[].filters[].extensionRef, Traefik used the backend Service namespace instead of the HTTPRoute namespace. A low-privileged route author holding a ReferenceGrant for a cross-namespace Service could therefore bind a Traefik Middleware from the backend namespace without a separate grant for that middleware, potentially injecting trusted reverse-proxy identity headers into downstream requests. The issue is fixed in version 3.7.7.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | Traefik | ≥ 3.7.0&&< 3.7.7 | 3.7.7go get Traefik@v3.7.7 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for Traefik, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update Traefik to 3.7.7 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-65601 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2026-65601 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2026-65601. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Fixing This On Your OS
If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.
This is an Important flaw in Traefik's Kubernetes Gateway API provider, affecting Red Hat OpenShift Dev Spaces. A low-privileged user in a Kubernetes environment can exploit a namespace confusion vulnerability to bypass security controls. This allows for the incorrect binding of a Traefik Middleware from a different…
| Product | Fixed in | Advisory |
|---|---|---|
| Red Hat OpenShift Dev Spaces 3.30 | devspaces/traefik-rhel9:1787756799 | RHSA-2026:62260 |
Frequently Asked Questions
Is CVE-2026-65601 in your dependencies?
O3 Security finds CVE-2026-65601 across Go dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.