GitHub Advisoryadvisory · Go

GHSA-m5ch-ppfx-xv3v Gitea OAuth2 PKCE S256 verifier bypass

CRITICAL Published 2026-07-03 Modified 2026-09-01 Official page ↗
Aliases
CVE-2026-26247
Ecosystem
Go
Packages
code.gitea.io/gitea
Severity
Critical
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
Weaknesses
CWE-284
Reviewed
2026-09-01

Affected packages

• Go code.gitea.io/gitea: < 1.25.5 → fixed in 1.25.5

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.

Related

Alias · CVE (1)

  • CVE-2026-26247 Gitea versions before 1.25.5 do not persist the OAuth2 PKCE S256 challenge method correctly during authorization, allowing token exchange… vulnerability

Weakness · CWE (1)

  • CWE-284 Improper Access Control weakness

References