CVE-2026-20896 Gitea Docker image trusts spoofable reverse-proxy headers by default
Attackers can impersonate users via spoofed headers in default Gitea Docker configurations, requiring configuration changes to restrict trusted proxies.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-20896?
CVE-2026-20896 is a critical authentication bypass vulnerability in Gitea Open Source Git Server, published on 3 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
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.
Weakness: CWE-284
Which versions are affected by CVE-2026-20896?
3 open source packages ship an affected version, including code.gitea.io/gitea.
| Package | Affected | Fixed in |
|---|---|---|
code.gitea.io/gitea Go | All versions | 1.26.3 |
code.gitea.io/gitea Go | All versions | 1.26.3 |
code.gitea.io/gitea Go | All versions | 1.26.3 |
How do I fix CVE-2026-20896?
Upgrade code.gitea.io/gitea to 1.26.3 or later.
Upgrade, and rotate credentials and sessions that may have been exposed. More about Authentication bypass.
Is CVE-2026-20896 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-20896 exists.
Public exploit code: 1 Nuclei template and 8 proofs of concept on GitHub.
Sources
Also known as GHSA-f75j-4cw6-rmx4, GO-2026-6051.