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 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.

Score
CVSS 3.1 7.5 High
Status
Awaiting Analysis - 88ee5874-cf24-4952-aea0-31affedb7ff2
Published
2026-10-18
Last modified
2026-10-19

Affected products

References

 
 
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