Vulnerability in github.com/traefik/traefik/v3 (CVE-2026-54765)
Summary
Vulnerability in github.com/traefik/traefik/v3 (CVE-2026-54765). Data can be tampered with by attackers. Exploitable via backendRef. Mitigation: upgrade to 3.7.6 or later.
Original description
The description as published by the source.
Summary
There is a medium severity vulnerability in Traefik's Kubernetes Gateway API provider.
When two accepted HTTPRoutes target the same backend Service:port but configure different
backendRef filters, Traefik may resolve both routes to the same child service and apply
only one route's filter set to all requests reaching that backend. In Gateway deployments
where backendRef filters set security-sensitive headers — such as tenant identity,
authorization context, or values the backend trusts — an attacker who can create an
accepted HTTPRoute sharing the same backend Service:port may cause their route's filter
context to be applied to another route's requests, potentially crossing namespace
boundaries when a ReferenceGrant permits cross-namespace targeting.
Patches
For more information
If you have any questions or comments about this advisory, please open an issue.
Original Description
Traefik Gateway HTTPRoute backendRef filter context collision across routes sharing Service:port
Summary
Traefik's Kubernetes Gateway API provider builds the dynamic HTTP backend service key for a Gateway HTTPRoute backendRef from only the backend namespace, Service name, protocol, and port. It does not include the HTTPRoute, listener, rule, or backendRef filter identity in that key.
When two accepted HTTPRoutes point to the same backend Service:port but define…
Source: NIST National Vulnerability Database NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-54765 has been found in github.com/traefik/traefik/v3.
Attackers can target a specific entry point like backendRef over the network to misuse the product.
Data can be tampered with by attackers. CVSS score: 8.5/10.
What to do: upgrade github.com/traefik/traefik/v3 to 3.7.6 or later.
If unsure, ask your IT team or search "github.com/traefik/traefik/v3 CVE-2026-54765" on the vendor's site.
CVE-2026-54765 (github.com/traefik/traefik/v3) — CWE-284 / CVSS v3 8.5
Attack vector: remote (network-reachable) / no user interaction
Attack surface: backendRef / ReferenceGrant / HTTPRoute / loadService
Patched: 3.7.6 — apply immediately
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
A vulnerability (CWE-284) exists in github.com/traefik/traefik/v3. Attackers reach the vulnerable code path via backendRef.
Check the vendor advisory for the affected versions of github.com/traefik/traefik/v3. Attack surface: backendRef / ReferenceGrant / HTTPRoute / loadService.
Severity: High (CVSS 8.5/10). Data can be tampered with by attackers.
Update to 3.7.6.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'github.com/traefik/traefik/v3' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify exposure identify
grep -r 'github.com/traefik/traefik/v3' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
github.com/traefik/traefik/v3を grep し、稼働しているサービス・バージョンを把握する。 -
2Apply patch patch
Upgrade github.com/traefik/traefik/v3 to 3.7.6ステージング環境で 3.7.6 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスを含めること。
-
3Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
Affected packages
References
- advisory nvd.nist.gov
- package github.com
- web github.com
- web github.com
- web github.com
- web github.com
- web github.com