Unauthenticated authorization bypass via opaque request target
Published Sep 10, 2026 · Updated Sep 10, 2026
Authorization bypass in Traefik Proxy 2.11.56 and earlier and 3.0.0 through 3.7.12 allows remote attackers to reach protected paths. The rewriteRequestBuilder path evaluates an empty URL.Path as "/" but leaves the attacker-controlled URL.Opaque value intact for verbatim backend forwarding. Exploitation is unauthenticated under stock entrypoint defaults, but impact requires a backend that accepts the rootless target as a path; successful requests bypass path guards and evade accurate access logging.
Summary
What happened
Authorization bypass in Traefik Proxy 2.11.56 and earlier and 3.0.0 through 3.7.12 allows remote attackers to reach protected paths. The rewriteRequestBuilder path evaluates an empty URL.Path as "/" but leaves the attacker-controlled URL.Opaque value intact for verbatim backend forwarding. Exploitation is unauthenticated under stock entrypoint defaults, but impact requires a backend that accepts the rootless target as a path; successful requests bypass path guards and evade accurate access logging.
The record
- CVE
- CVE-2026-88009
- Published
- Sep 10, 2026
- Updated
- Sep 10, 2026
- Vendor
- Traefik Labs
- Product
- Traefik Proxy
- Classifications
- CWE-1286, CWE-444, T1190
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Sep 10, 2026CVE publishedPublication date reported by the CVE source.
- Sep 10, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
Compare your product and version with the public record. A matching version still requires validation against your environment.
Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=< 2.11.57
- Affected versionversion=>= 3.0.0, < 3.7.13
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
- Upstream opaque request-target reproductionfunctional · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
See the directory against your own environment.
Your stack
Check the software in your environment
Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.
Book a demo