Improper access control in Gitea - CVE-2026-20896
Published: June 22, 2026
Vulnerability identifier: #VU135010
CSH Severity: High
CVSS v4: 9.3 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-20896
CWE-ID: CWE-284
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to impersonate arbitrary users.
The vulnerability exists due to improper access control in reverse proxy authentication handling when processing the X-WEBAUTH-USER header from direct HTTP requests. A remote attacker can send a specially crafted request with an X-WEBAUTH-USER header to impersonate arbitrary users.
Only Docker image deployments are affected, and exploitation requires ENABLE_REVERSE_PROXY_AUTHENTICATION to be enabled.
Affected software
Gitea
How to mitigate CVE-2026-20896
Install security update from vendor's website.
Gitea - update to 1.26.3