CVE-2026-20896: Gitea Docker image: `REVERSE_PROXY_TRUSTED_PROXIES = *` default lets any source IP impersonate any user via `X-WEBAUTH-USER`

Severity: Critical

CVSS Score: 9.8

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.