CVE record
CVE-2026-26247
Gitea OAuth2 PKCE S256 challenges are not enforced during token exchange
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.
CVE evidence
Known exploitation
Not listed in fetched KEV catalog
Absence from the fetched catalog does not establish that exploitation has not occurred.
Severity
critical
CVSS 9.1 · CVSS_V3
Affected packages
1
Supported package records returned by OSV. Vendor and product names are not used to infer matches.
OSV package mapping
Affected open-source packages
| Package | Ecosystem | Fixed versions |
|---|---|---|
| code.gitea.io/gitea | go | 1.25.5 |