---
cve: "CVE-2026-20896"
severity: "CRITICAL"
cvss: 9.8
epss: "62.4%"
vendor: "Gitea"
kev: false
exploited: false
published: "2026-07-03 21:16:56"
tags: [cve, security, critical]
source: tsecurity.de CVE-Dossier
exported: "2026-09-07T12:18:15+02:00"
---

# CVE-2026-20896

> 9.8 CRITICAL · 🧪 PoC

## Beschreibung

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.

## CVSS-Vektor

```
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
```

| Metrik | Wert | Bewertung |
|---|---|---|
| AV Angriffsvektor | Netzwerk | bad |
| AC Komplexität | Gering | bad |
| PR Privilegien | Keine | bad |
| UI Interaktion | Keine | bad |
| S Scope | Unverändert | good |
| C Vertraulichkeit | Hoch | bad |
| I Integrität | Hoch | bad |
| A Verfügbarkeit | Hoch | bad |

## Patch verfügbar (OSV)

- 4aa0d704f2c7d30351016b740bfc45247fd77efa (Commit)

## Referenzen

- <https://github.com/go-gitea/gitea/security/advisories/GHSA-f75j-4cw6-rmx4>
- <https://github.com/go-gitea/gitea/pull/38151>
- <https://github.com/go-gitea/gitea/releases/tag/v1.26.3>
- <https://blog.gitea.com/release-of-1.26.3-and-1.26.4/>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-20896) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_