---
title: "CVE-2026-109553: Gitea - Authentication Bypass"
description: "Gitea contains an authentication bypass caused by improper principal resolution in SSH certificate handling, letting attackers authenticate as other users via HTTP signature API and SSH server, exploit requires trusting user certificate authority and accepting arbitrary principals."
url: https://panop.io/threat-heartbeat/CVE-2026-109553/
---

# CVE-2026-109553 Gitea - Authentication Bypass

Gitea contains an authentication bypass caused by improper principal resolution in SSH certificate handling, letting attackers authenticate as other users via HTTP signature API and SSH server, exploit requires trusting user certificate authority and accepting arbitrary principals.

CVSS base score 7.5 /10

High

CISA KEV

Not listed

Public exploit

None known

EPSS

0.10% chance of exploitation in 30 days

[View the NVD record ↗](https://nvd.nist.gov/vuln/detail/CVE-2026-109553)

## Details

Type

Authentication Bypass

Impact

Broken Authentication

CVSS vector

CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H

Published

18 October 2026

Updated

20 October 2026

## Vendor fix

Update to the latest version that fixes principal resolution in SSH certificate handling.

Patching closes this CVE. It does not tell you which of your systems run the affected version, or what else is exposed alongside them.

## References

- [https://nvd.nist.gov/vuln/detail/CVE-2026-109553](https://nvd.nist.gov/vuln/detail/CVE-2026-109553)
- [https://github.com/go-gitea/gitea/releases/tag/v28.2.0](https://github.com/go-gitea/gitea/releases/tag/v28.2.0)
- [https://github.com/go-gitea/gitea/security/advisories/GHSA-vcp6-2qc6-gvq3](https://github.com/go-gitea/gitea/security/advisories/GHSA-vcp6-2qc6-gvq3)
- [https://blog.gitea.com/release-of-28.2.0/](https://blog.gitea.com/release-of-28.2.0/)
- [https://github.com/go-gitea/gitea/pull/39839](https://github.com/go-gitea/gitea/pull/39839)
- [https://github.com/go-gitea/gitea/pull/39847](https://github.com/go-gitea/gitea/pull/39847)

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## What this record can't tell you

- Whether you run the affected software, and where
- Whether an attacker can actually reach and exploit it
- The misconfigurations that never get a CVE number
- What it would cost the business, ranked into what to fix first

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