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.
Published:
2026-10-18
Score:
n/a
EPSS:
n/a
KEV:
No
Impact:
n/a
Action:
n/a
Analysis
No analysis available yet.
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | ||||||
|---|---|---|---|---|---|---|---|---|---|
| Gitea | Gitea | unaffected |
|
No data.
No data.
No data available yet.
Remediation
No remediation available yet.
Tracking
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Advisories
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References
History
Sun, 18 Oct 2026 19:00:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| 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. | |
| Title | Gitea SSH certificate principal impersonation of other users | |
| References |
|
Subscriptions
No data.
MITRE
Status: PUBLISHED
Assigner: Gitea
Published:
Updated: 2026-10-18T18:51:31.037Z
Reserved: 2026-10-14T20:08:45.856Z
Link: CVE-2026-109553
Vulnrichment
No data.
NVD
Status : Received
Published: 2026-10-18T19:16:32.997
Modified: 2026-10-18T19:16:32.997
Link: CVE-2026-109553
Redhat
No data.
OpenCVE Enrichment
No data.
Weaknesses
No weakness.