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
AI Analysis

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Remediation

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History

Sun, 18 Oct 2026 21:15:00 +0000

Type Values Removed Values Added
Weaknesses CWE-287

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

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cve-icon MITRE

Status: PUBLISHED

Assigner: Gitea

Published:

Updated: 2026-10-18T18:51:31.037Z

Reserved: 2026-10-14T20:08:45.856Z

Link: CVE-2026-109553

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-10-18T19:16:32.997

Modified: 2026-10-18T19:16:32.997

Link: CVE-2026-109553

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-10-18T21:00:10Z

Weaknesses