DemoBook a demo

Vulnerability advisory

GHSA-m5ch-ppfx-xv3v

Gitea OAuth2 PKCE S256 verifier bypass

Published Updated OSV record ↗

Also known as CVE-2026-26247GO-2026-6342

Severity
  • CVSS 3.xCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

Affected versions

code.gitea.io/gitea Go

All code.gitea.io/gitea advisories →
AffectedFixed in
All versions before 1.25.51.25.5

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.

References

  • Codex
  • Claude Code
  • VS Code
  • GitHub Copilot
  • Cursor
  • Cline
  • Windsurf
  • Google Anti-gravity
  • OpenCode
  • Pi
  • Gemini CLI
  • Hermes Agent
  • Zed
  • Junie
  • Qwen Code
  • Kiro
  • Kilo Code
  • Factory Droid

Set up GitHits for your agents

Run this command:

<> bash
npx githits@latest init

What happens next:

  1. Opens your browser to authorize GitHits
  2. Asks whether to set up GitHits at the user or project level
  3. Detects your supported AI coding tools
  4. Lets you choose which tools to configure
  5. Configures the selected tools

Having trouble? Check our documentation.