CVE-2026-26247: Gitea OAuth2 PKCE S256 verifier bypass
(updated )
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.
References
- blog.gitea.com/release-of-1.25.5
- github.com/advisories/GHSA-m5ch-ppfx-xv3v
- github.com/go-gitea/gitea/commit/750649c1ef092c95f95b206b9d5fa17471a0b1f5
- github.com/go-gitea/gitea/commit/bf8d11bb212ba2a76596d8a90e74e7d664571324
- github.com/go-gitea/gitea/pull/36462
- github.com/go-gitea/gitea/pull/36477
- github.com/go-gitea/gitea/releases/tag/v1.25.5
- nvd.nist.gov/vuln/detail/CVE-2026-26247
Code Behaviors & Features
Detect and mitigate CVE-2026-26247 with GitLab Dependency Scanning
Secure your software supply chain by verifying that all open source dependencies used in your projects contain no disclosed vulnerabilities. Dependency Scanning using SBOM also detects vulnerabilities from proprietary advisories that this site does not include. Learn more about Dependency Scanning using SBOM →