CVE-2026-20896
Gitea Docker image trusts spoofable reverse-proxy headers by default
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.
INFO
Published Date :
July 3, 2026, 9:16 p.m.
Last Modified :
July 7, 2026, 6:16 p.m.
Remotely Exploit :
Yes !
Source :
88ee5874-cf24-4952-aea0-31affedb7ff2
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | CRITICAL | 88ee5874-cf24-4952-aea0-31affedb7ff2 |
Solution
- Update Gitea to version 1.21.6 or later.
- Set REVERSE_PROXY_TRUSTED_PROXIES appropriately.
- Limit access to trusted reverse proxy IPs.
- Disable if no reverse proxy is used.
Public PoC/Exploit Available at Github
CVE-2026-20896 has a 13 public
PoC/Exploit available at Github.
Go to the Public Exploits tab to see the list.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-20896.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-20896 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-20896
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
this is a modified POC of rz1027 for CVE-2026-20896
cve gitea poc
Python
Personal exploit library — verified CVE PoCs rewritten from scratch
Python
CVE-2026-20896 Gitea Docker X-WEBAUTH-USER auth bypass checker
Go Shell
Public PoC and detector for CVE-2026-20896 ("Gitea Docker: One Header, Any User")
Python
Public PoC and detector for CVE-2026-20896 ("Gitea Docker: One Header, Any User")
cve gitea poc takeover
Python
252 standalone, live-validated CVE exploit PoCs (pure-Python stdlib) across web apps, AI/ML platforms and the Linux kernel; 75 in the CISA KEV catalog. For authorized security testing and education.
cve exploit penetration-testing poc security-research vulnerability cybersecurity ethical-hacking infosec rce red-team security appsec cisa-kev deserialization exploit-development proof-of-concept python
Python C
None
Python
Each day I try and post the newest security news
HTML
None
None
Shell
None
None
📡 PoC auto collect from GitHub. ⚠️ Be careful Malware.
security cve exploit poc vulnerability
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-20896 vulnerability anywhere in the article.
-
The Hacker News
Threat Actors Probe Gitea Docker Flaw CVE-2026-20896 13 Days After Disclosure
Threat actors have been observed attempting to exploit a recently patched critical security flaw in Gitea Docker images, according to Sysdig. The vulnerability in question is CVE-2026-20896 (CVSS scor ... Read more
The following table lists the changes that have been made to the
CVE-2026-20896 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Jul. 07, 2026
Action Type Old Value New Value Added Reference https://github.com/go-gitea/gitea/security/advisories/GHSA-f75j-4cw6-rmx4 Added SSVC {'id': 'CVE-2026-20896', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'poc'}, {'automatable': 'yes'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-07-06T19:03:07.590667Z'} -
New CVE Received by 88ee5874-cf24-4952-aea0-31affedb7ff2
Jul. 03, 2026
Action Type Old Value New Value Added Affected [{'vendor': 'Gitea', 'product': 'Gitea Open Source Git Server', 'versions': [{'status': 'affected', 'version': '0', 'versionType': 'semver', 'lessThanOrEqual': '1.26.2'}], 'defaultStatus': 'unaffected'}] Added 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. Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Added CWE CWE-284 Added Reference https://blog.gitea.com/release-of-1.26.3-and-1.26.4/ Added Reference https://github.com/go-gitea/gitea/pull/38151 Added Reference https://github.com/go-gitea/gitea/releases/tag/v1.26.3 Added Reference https://github.com/go-gitea/gitea/security/advisories/GHSA-f75j-4cw6-rmx4