Is CVE-2026-109553 being exploited?

No public exploit is currently tracked.

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CVE-2026-109553

Description

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.

Threat reporting mentioning CVE-2026-109553

Gitea Releases Security Update for Multiple VulnerabilitiesGitea has released version 28.2.0, addressing several security vulnerabilities, including CVE-2026-104627, which allows an attacker to link their OpenID identity to a victim's acco…