CVE-2026-20896: Gitea Docker image trusts spoofable reverse-proxy headers by default

Is it exploited?

Reported, not confirmed by CISA. VulnCheck KEV lists it as exploited in the wild. CISA has not added it to its Known Exploited Vulnerabilities catalog as of 29 Oct 2026.

VulnCheck KEV lists it since 6 Jul 2026. It cites 3 public reports, the first from 6 Jul 2026.

• linkedin.com
• csa.gov.sg
• previdian.com

How likely is exploitation in the next 30 days?

2.8%

EPSS score, percentile 86.2 of all scored records. A probability estimated by FIRST, not a report of exploitation.

CISA's SSVC assessment in the CVE record lists exploitation as poc.

How severe?

9.8 Critical

CVSS v3.1 base score, given by the CNA

What should I do?

CISA has set no required action, because the vulnerability is not in KEV.

Advisories and patches (4)

Which versions are affected?

Affected

• 1.26.2 and earlier

Versions by product

Source: CISA KEV 2026.10.29, as of 29 Oct 2026; VulnCheck KEV, as of 30 Oct 2026; FIRST EPSS, as of 30 Oct 2026; CVE List, as of 30 Oct 2026. About the data.

Description

Gitea Docker image trusts spoofable reverse-proxy headers by default

Gitea Docker image versions up to and including 1.26.2 use REVERSE_PROXY_TRUSTED_PROXIES=* by default, allowing any source IP to impersonate a user when reverse-proxy authentication headers such as X-WEBAUTH-USER are enabled.

Source: CVE List, as of 30 Oct 2026. About the data.

What to do

Advisories and patches

• GitHub Pull Request #38151 (Patch)
• GitHub Security Advisory (Vendor advisory)
• Gitea v1.26.3 Release (Release notes)
• Gitea v1.26.4 Release Blog Post (Release notes)

This summary is based on the CVE record as of 30 Oct 2026. Check the vendor's advisory before you act: affected versions and fixes can change.

Affected products and versions

Source: CVE List, as of 30 Oct 2026. About the data.

Timeline

Known exploited Gitea vulnerabilities

• CVE-2026-60004: Gitea Code Injection Vulnerability (added 25 Aug 2026)