Authentication bypass in Gitea SSH server through key case folding
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- High · High · None
- Fix status
- No fix listed
Attack profile from CVSS 3.1 · CISA ADP. Fix status from CNA.
Summary
Gitea through 1.27.3 is affected when its built-in SSH server is enabled. Key lookup uses a case-insensitive SQL LIKE comparison, which causes an authentication bypass (CWE-305). An unauthenticated remote attacker who can derive the private key for a case variant of another user's registered RSA public key can authenticate over SSH as that user.
Written with Claude Haiku 5.5 from the sources below · 2026-10-29
Description from the CNA
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.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- Yes
- Technical impact
- Total
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
Remediation
The sources list no fixed version for Gitea.
Written with Claude Haiku 5.5 from the sources below · 2026-10-29
Vendor assessments
Timeline
- 2026-10-06 Threatist record created from CVE-2026-103059
- 2026-10-07 Affected versions changed · Red Hat
- 2026-10-07 CVSS score added · Red Hat
- 2026-10-07 CVSS score added · CISA ADP
- 2026-10-07 Weakness changed · CISA ADP
- 2026-10-07 CISA SSVC decision points changed
- 2026-10-07 Priority changed: LOW → MEDIUM
References
More Gitea vulnerabilities
- TI-2026-42785 Gitea before 1.27.1 allows remote code execution via the diffpatch API through Git hook installation. KEVCVSS 3.1CRITICAL 9.8
- TI-2020-11072 The git hook feature in Gitea 1.1.0 through 1.12.5 might allow for authenticated remote… CVSS 3.1HIGH 7.2
- TI-2022-12910 Gitea before 1.16.7 does not escape git fetch remote. CVSS 3.1HIGH 7.5
- TI-2019-08404 models/repo_mirror.go in Gitea before 1.7.6 and 1.8.x before 1.8-RC3 mishandles mirror… CVSS 3.1HIGH 8.8
- TI-2022-00955 Open Redirect on login in go-gitea/gitea CVSS 3.1MEDIUM 6.1
- TI-2026-68968 Push-to-create bypass of FORCE_PRIVATE policy in Gitea CVSS 3.1MEDIUM 5.4
Sources
- CVE-2026-103059 · CVE Program
- CVE-2026-103059 · NVD
- FIRST EPSS
- CVE-2026-103059 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences