Go to homepageCyberStrike

Menu

Star on GitHub · 3.4k
Sign inDownload

CVE-2026-109553

7.5 · HIGH

Gitea resolved the principals of an SSH certificate by searching the content of all stored public keys instead of only principal keys.

Published Oct 18, 2026CWE-287EPSS 0.20%

Overview

CVE-2026-109553 is a high-severity vulnerability. It was published on October 18, 2026 and has a CVSS 3.1 base score of 7.5 (HIGH).

This vulnerability has a CVSS 3.1 base score of 7.5, rated HIGH. It can be exploited remotely over the network. Some level of privileges is required for exploitation.

Technical 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.

Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

References

Refblog.gitea.com/release-of-28.2.0/GitHubgithub.com/go-gitea/gitea/pull/39839GitHubgithub.com/go-gitea/gitea/pull/39847GitHubgithub.com/go-gitea/gitea/releases/tag/v28.2.0GitHubgithub.com/go-gitea/gitea/security/advisories/GHSA-vcp6-2qc6-gvq3

How CyberStrike helps

Frequently asked questions

What is CVE-2026-109553?

CVE-2026-109553 is a high-severity vulnerability. It was published on October 18, 2026 and has a CVSS 3.1 base score of 7.5 (HIGH).

How severe is CVE-2026-109553?

This vulnerability has a CVSS 3.1 base score of 7.5, rated HIGH. It can be exploited remotely over the network. Some level of privileges is required for exploitation.

How do I fix or remediate CVE-2026-109553?

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

How can CyberStrike help with CVE-2026-109553?

CyberStrike is an open-source, AI-augmented pentesting engine. Rather than flag a version number, it tests whether an issue like CVE-2026-109553 is actually reachable in your own applications and APIs, then verifies each finding before reporting it. That tells you if the weakness is a real, exploitable risk in your environment or a false positive you can safely deprioritize.

Related HIGH CVEs from 2026

View all
Browse by year2026202520242023202220212020201920182017201620152014201320122011201020092008200720062005200420032002200120001999
Watch the demo →