Critical 9.1Published Jul 3, 2026

CVE-2026-26247Gitea OAuth2 PKCE S256 challenges are not enforced during token exchange

Updated under an hour ago (Oct 27, 2026, 4:00 PM ET)

Does this affect you?

It affects Gitea Open Source Git Server. Add what you run to find out whether that includes you.

No exploitation reported and no EPSS estimate yet.

Do this next

Start free and add your stack

Free account, 1 product

Every CVE for Gitea Open Source Git Server

Exploited in the last 30 days

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: 9.1 CRITICAL (v3.1, CISA ADP)CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
Weakness (CWE): CWE-284
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: Gitea
NVD analysis: Deferred
Record last updated: Jul 7, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

Gitea Gitea Open Source Git Server gitea:open_source_git_server (from the name)	before 1.25.5	CNA record

References

References

https://github.com/go-gitea/gitea/pull/36462	patch
https://github.com/go-gitea/gitea/pull/36477	patch
https://github.com/go-gitea/gitea/releases/tag/v1.25.5	release-notes
https://blog.gitea.com/release-of-1.25.5/	release-notes

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.