Unauthenticated authorization bypass via forwarded-port spoofing
Published Jul 6, 2026 · Updated Jul 6, 2026
Header authenticity failure in Traefik Proxy allows remote attackers to bypass port-based authorization over plain HTTP. The ForwardAuth writeHeader path calls forwardedPort with the original request, so an injected X-Forwarded-Proto value makes the sanitized authentication request carry X-Forwarded-Port 443. Exploitation requires ForwardAuth with trustForwardHeader disabled and an authentication service that grants access based on the forwarded port.
Summary
What happened
Header authenticity failure in Traefik Proxy allows remote attackers to bypass port-based authorization over plain HTTP. The ForwardAuth writeHeader path calls forwardedPort with the original request, so an injected X-Forwarded-Proto value makes the sanitized authentication request carry X-Forwarded-Port 443. Exploitation requires ForwardAuth with trustForwardHeader disabled and an authentication service that grants access based on the forwarded port.
The record
- CVE
- CVE-2026-54764
- Published
- Jul 6, 2026
- Updated
- Jul 6, 2026
- Vendor
- Traefik Labs
- Product
- Traefik Proxy
- Classifications
- CWE-345, T1190
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jul 6, 2026CVE publishedPublication date reported by the CVE source.
- Jul 6, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=< 2.11.51
- Affected versionversion=>= 3.0.0, < 3.6.22
- Affected versionversion=>= 3.7.0, < 3.7.6
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- ForwardAuth X-Forwarded-Port spoofing proof of conceptproof of concept · demonstrated
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Technologies
Your stack
See the directory against your own environment.
Your stack
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