CVE-2026-54765: Traefik incorrect authorization via backendRef filter collision in Kubernetes Gateway API

CVE-2026-54765 · Severity: medium · CVSS 4 · Published 2026-07-06

A vulnerability in Traefik's Kubernetes Gateway API provider can cause security settings to be incorrectly shared between different web routes. If two routes point to the same backend service but use different security rules (like adding identity headers), Traefik may accidentally apply one route's rules to the other. This could allow an attacker to bypass security controls or impersonate other users by leaking sensitive context across different parts of the network.

Technologies: github.com/traefik/traefik (Go), github.com/traefik/traefik/v2 (Go), github.com/traefik/traefik/v3 (Go). Vendors: Go.

Quick answers

Is CVE-2026-54765 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-54765 being exploited in the wild.
How severe is CVE-2026-54765?
Medium severity, with a CVSS score of 4, published 6 July 2026.
Which products and versions are affected?
github.com/traefik/traefik (Go) SEMVER:introduced=0; github.com/traefik/traefik/v2 (Go) SEMVER:introduced=0; github.com/traefik/traefik/v3 (Go) >= 3.7.0, <= 3.7.5, SEMVER:introduced=3.7.0,fixed=3.7.6.
Is there a fix for CVE-2026-54765?
Yes. github.com/traefik/traefik/v3 (Go): upgrade to 3.7.6 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-54765 attacked?
It is attacked over the network, in a software library.
Am I affected by CVE-2026-54765?
Check whether you run github.com/traefik/traefik (Go), github.com/traefik/traefik/v2 (Go) or github.com/traefik/traefik/v3 (Go) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

  • github.com/traefik/traefik/v3 (Go): upgrade to 3.7.6 or later
    go get github.com/traefik/traefik/v3@v3.7.6

Technical details

The vulnerability exists in Traefik's Kubernetes Gateway API provider within `pkg/provider/kubernetes/gateway/httproute.go`. When generating dynamic HTTP backend service keys for `HTTPRoute` `backendRef`, Traefik uses only the namespace, Service name, protocol, and port, omitting the route or filter identity. If two routes target the same backend Service:port with different `backendRef` filters, the generated keys collide, and one configuration overwrites the other during the `maps.Copy` merge process. An attacker with permission to create an `HTTPRoute` can exploit this to force their filter context (e.g., headers used for auth or multi-tenancy) onto a victim's route. This is particularly impactful in cross-namespace deployments where `ReferenceGrant` is used.

Affected products

  • traefik traefik >= 3.7.0, <= 3.7.5

Identifiers

  • CVE-2026-54765
  • GHSA-6p8f-p8j2-rqmv
  • GO-2026-6205

Timeline

  • 2026-06-04: disclosed: Discovered and reproduced by researchers.
  • 2026-07-01: advisory: Initial GitHub Advisory published.
  • 2026-08-06: patched: Version 3.7.6 released.

References

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