HIGHCVSS v3.1 7.5Vulnerability
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.
Properties
- Severity
- HIGH
- Nvd fetched at
- 2026-10-20T21:14:08.448323+00:00
- Cvss severity
- HIGH
- Cvss score
- 7.5
- Epss score
- 0.00198
- Retrieved at
- 2026-10-21T01:24:48+00:00
- Last source
- FIRST EPSS
- Cvss version
- 3.1
- Score
- 7.5
- Cve id
- CVE-2026-109553
- Cvss vector
- CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
- First seen by Signal
- 2026-10-18T22:14:59+00:00
- Vector
- CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
- Published at
- 2026-10-18T19:16:32.997
- Last modified
- 2026-10-19T21:17:04.780
- Epss percentile
- 0.08925
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