7.5

CVE-2026-109553: gitea

CVSS: 7.5v3.1HighAwaiting analysis
Published 18-10-2026Last modified 19-10-2026
Open JSON

Vulnerability summary

CVE-2026-109553 is a high (CVSS 7.5) vulnerability in gitea. EPSS estimates a 0.20% chance of exploitation in the next 30 days, higher than 8.9% of scored vulnerabilities.

Overall risk
30/100
0100
Medium · default modelHow is this calculated?
CVSS score
7.5/10
010
High · v3.1 (CVE.org)
EPSS score
0.20%
0%100%
Low · Change unavailable
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Timeline

  1. 18-10-2026
    PublishedVulnerability first disclosed.
  2. 19-10-2026
    Last modifiedVulnerability information updated.

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.

CVSS metrics

2 scores · 2 sources · 1 version

EPSS trend

Probability

0.20%

Chance of exploitation in the next 30 days

Percentile

9%

Versus all other CVEs

30-day change

Change unavailable

Change unavailable

19-10-202620-10-2026
EPSS score
0.20%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

No weakness data has been published for this record.

Affected systems

Gitea1 product

1 vendor · 1 product

References

5 links