CVE-2026-109553: high-severity vulnerability in Gitea
Gitea SSH certificate principal impersonation of other users
Published · Updated
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21Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 7.5epss 0.2%
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.
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
Affected products
Gitea · GiteaRelated CVEs — Gitea
In the same product, most dangerous first.
CVE-2026-60004CRITICALCVE-2026-60004EPSS 24.0%KEVCVE-2026-59774CRITICALGitea Org-mode file disclosure and code executionEPSS 28.3%CVE-2019-1010314—CVE-2019-1010314EPSS 0.8%CVE-2019-1010261—CVE-2019-1010261EPSS 0.8%CVE-2026-94205CRITICALGitea fork workflow approval bypass through maintainer-triggered eventsEPSS 0.6%CVE-2026-96404HIGHGitea installer authentication bypass for existing accountsEPSS 0.6%