Authentication bypass via wildcard trusted-proxy default
Published Jul 3, 2026 · Updated Jul 3, 2026
Authentication bypass in Gitea Docker images 1.26.2 and earlier allows remote attackers to impersonate users through HTTP headers. The root and rootless app.ini templates set REVERSE_PROXY_TRUSTED_PROXIES to *, so the proxy-origin check accepts X-WEBAUTH-USER from every source address. Reverse-proxy authentication must be enabled, and the attacker must reach the container port directly or through a proxy that preserves the forged header.
Summary
What happened
Authentication bypass in Gitea Docker images 1.26.2 and earlier allows remote attackers to impersonate users through HTTP headers. The root and rootless app.ini templates set REVERSE_PROXY_TRUSTED_PROXIES to *, so the proxy-origin check accepts X-WEBAUTH-USER from every source address. Reverse-proxy authentication must be enabled, and the attacker must reach the container port directly or through a proxy that preserves the forged header.
The record
- CVE
- CVE-2026-20896
- Published
- Jul 3, 2026
- Updated
- Jul 3, 2026
- Vendor
- Gitea
- Product
- Gitea
- Classifications
- CWE-284, T1190
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jul 3, 2026CVE publishedPublication date reported by the CVE source.
- Jul 3, 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=0 <=1.26.2
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.
Public exploit references
- szybnev Gitea X-WEBAUTH-USER bypass checkerfunctional · demonstrated
- CVE-2026-20896 Gitea authentication-bypass PoC and detectorfunctional · demonstrated
- EQSTLab Gitea Docker image authentication-bypass PoCfunctional · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Reported exploitation
- Reported active exploitation of the Gitea Docker authentication bypassreported exploitation
Technologies
Your stack
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Your stack
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