Track vulnerabilities like this one. Sign up free to get alerted when software you use is affected.
9.1

Gitea SSH server may allow login with modified key

CVE-2026-103059 · published 3 days ago
Summary

If Gitea's built‑in SSH server is turned on, it checks public keys in a way that ignores letter case. An attacker who creates a key that is the same as a legitimate user's key except for different capitalization could be treated as that user and log in via SSH. Update Gitea to the latest release (which matches keys by fingerprint) or disable the built‑in SSH server and use an external SSH service.

What to do

The CVE record does not list a fixed version. Check the vendor's site or the advisory links below - a fix may already be released.

Affected software
VendorProductAffected versions
gitea gitea <= 1.27.3
Original advisory text
Gitea built-in SSH server authentication bypass through key case folding
When Gitea's built-in SSH server is enabled (`START_SSH_SERVER = true`), the presented public key was looked up with an SQL `LIKE` comparison of its encoded content, which is case-insensitive on some databases, including the default SQLite. An attacker who can construct a case variant of another user's registered RSA public key for which they can derive the private key could have that key matched to the victim's account and authenticate over SSH as that user. Keys are now looked up by fingerprint.
References
Fix within
Internet-facing 3 days
Internal 60 days
  • Not known to be exploited
  • Can be exploited automatically
  • Gives an attacker full control
Severity
9.1 Critical
Exploitation
<1% chance of attack within 30 days
Type
CWE-305Authentication Bypass by Primary Weakness
Timeline
Published6 Oct 2026
Updated9 Oct 2026
First seen6 Oct 2026
Sources
CVE-2026-103059 · NVD
CVE-2026-103059 · MITRE
CVE-2026-103059 · OSV
GHSA-8pwg-hcgm-54cp · GHSA
Track software like this
Free during beta