Vulnerability Description
Gitea versions before 1.25.5 do not persist the OAuth2 PKCE S256 challenge method correctly during authorization, allowing token exchange without the expected verifier check.
CVSS Score
9.1
CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
Related Weaknesses (CWE)
References
- https://blog.gitea.com/release-of-1.25.5/
- https://github.com/go-gitea/gitea/pull/36462
- https://github.com/go-gitea/gitea/pull/36477
- https://github.com/go-gitea/gitea/releases/tag/v1.25.5
FAQ
What is CVE-2026-26247?
CVE-2026-26247 is a vulnerability with a CVSS score of 9.1 (CRITICAL). Gitea versions before 1.25.5 do not persist the OAuth2 PKCE S256 challenge method correctly during authorization, allowing token exchange without the expected verifier check.
How severe is CVE-2026-26247?
CVE-2026-26247 has been rated CRITICAL with a CVSS base score of 9.1/10. This is considered a critical vulnerability requiring immediate attention.
Is there a patch for CVE-2026-26247?
Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.