CVE-2026-109553
Gitea resolved the principals of an SSH certificate by searching the content of all stored public keys instead of only principal keys. When
CVSS
7.5
High
EPSS
0.1%
p1
KEV
—
Exploit Today
0
0-100
Published: Oct 18, 2026 · Last modified: Oct 19, 2026
Not enough EPSS history yet.
Gitea resolved the principals of an SSH certificate by searching the content of all stored public keys instead of only principal keys. When Gitea trusts a user certificate authority (`SSH_TRUSTED_USER_CA_KEYS`) and accepts arbitrary principals (`SSH_AUTHORIZED_PRINCIPALS_ALLOW=anything`), a user could register another user's public key line as their own principal, or a holder of a certificate signed by that authority could list it, and then authenticate as the owner of that key through the HTTP signature API and the built-in SSH server. Instances that do not trust a user certificate authority are not affected.
- blog.gitea.comhttps://blog.gitea.com/release-of-28.2.0/
- github.comhttps://github.com/go-gitea/gitea/pull/39839
- github.comhttps://github.com/go-gitea/gitea/pull/39847
- github.comhttps://github.com/go-gitea/gitea/releases/tag/v28.2.0
- github.comhttps://github.com/go-gitea/gitea/security/advisories/GHSA-vcp6-2qc6-gvq3
No related CVEs by CWE or product.