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PatchSiren cyber security CVE debrief

CVE-2026-54764 traefik CVE debrief

The Traefik ForwardAuth middleware is vulnerable to an authorization bypass. An unauthenticated remote attacker can inject an X-Forwarded-Proto: https header over a plain HTTP connection, causing Traefik to forward X-Forwarded-Port: 443 to the authentication service. This issue is fixed in Traefik versions v2.11.51, v3.6.22, and v3.7.6. Affected product deployments should be reviewed for exposure.

Vendor
traefik
Product
Unknown
CVSS
MEDIUM 6.9
CISA KEV
Not listed in stored evidence
Original CVE published
2026-07-06
Original CVE updated
2026-07-08
Advisory published
2026-07-06
Advisory updated
2026-07-08

Who should care

Users of Traefik who rely on the ForwardAuth middleware for authorization should be aware of this vulnerability and take steps to mitigate it. Operators, platform administrators, vulnerability management teams, and security teams may be impacted.

Technical summary

The Traefik ForwardAuth middleware, even when configured with trustForwardHeader: false, derives the X-Forwarded-Port header sent to the authentication service from the original incoming request instead of the sanitized forwarded request. This allows an unauthenticated remote attacker to inject an X-Forwarded-Proto: https header over a plain HTTP connection and cause Traefik to forward X-Forwarded-Port: 443 to the authentication service, bypassing port-based authorization checks.

Defensive priority

High

Recommended defensive actions

  • Upgrade to Traefik version v2.11.51, v3.6.22, or v3.7.6 or later
  • Verify and restrict the X-Forwarded-Port header in your authentication service
  • Monitor and review authentication service logs for suspicious activity
  • Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up
  • Review compensating controls for exposed systems while remediation is scheduled and verified
  • Check relevant monitoring, detection, and logs for exposed assets that need extra review
  • Track exceptions, retest remediated assets, and close the item only after evidence is documented

Evidence notes

The CVE record was published on 2026-07-06T21:16:56.930Z and has been modified since then. The NVD entry is currently Undergoing Analysis. Evidence is limited, and defenders should verify affected scope and vendor guidance.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-54764 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-54764

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2026-54764 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-54764

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.