{"id":"CVE-2026-20896","published":"2026-07-03T20:19:29Z","modified":"2026-07-07T17:00:46Z","title":"Gitea Docker image trusts spoofable reverse-proxy headers by default","vendor":"Gitea","product":"Gitea Open Source Git Server","tier":"core","eol":null,"affectedVersions":[{"vendor":"Gitea","product":"Gitea Open Source Git Server","versions":["<= 1.26.2"]}],"description":{"text":"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.","provenance":"source","from":"CVE.org"},"summary":{"text":"The Gitea Open Source Git Server, as shipped in its Docker image, trusts reverse-proxy authentication headers from any source IP by default because REVERSE_PROXY_TRUSTED_PROXIES is set to *, which is an improper access control flaw. An attacker who can reach the instance directly over the network can impersonate any user by sending a spoofed X-WEBAUTH-USER header, provided reverse-proxy authentication is enabled in the configuration.","provenance":"ai","model":"claude-haiku-5-5","generatedAt":"2026-10-30T13:36:36Z"},"cvss":{"score":9.8,"severity":"CRITICAL","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","provenance":"source","from":"CVE.org CNA"},"epss":{"score":0.02755,"percentile":0.86219,"date":"2026-10-30","provenance":"source"},"kev":null,"vulncheckKev":{"dateAdded":"2026-07-06","exploitedFirstSeen":"2026-07-06","ransomware":false,"evidence":[{"url":"https://www.linkedin.com/feed/update/urn:li:activity:7479652557561454592/","date":"2026-07-06"},{"url":"https://www.csa.gov.sg/alerts-and-advisories/alerts/al-2026-083/","date":"2026-07-08"},{"url":"https://previdian.com/CVE-2026-20896","date":"2026-10-20"}],"evidenceTotal":3,"provenance":"source"},"exploited":true,"otx":{"pulseCount":9,"pulses":[{"name":"PaperCut NG/MF Zero-Day RCE Chain CVE-2026-81578 / CVE-2026-82078","url":"https://otx.alienvault.com/pulse/6a9fa6abcde187c104f12ddb","created":"2026-09-08"},{"name":"CVE-2026-82329 JFrog Artifactory Auth Bypass — Admin Token Forgery (Active Exploitation)","url":"https://otx.alienvault.com/pulse/6a9a5fa31808ac89ed23288a","created":"2026-09-04"},{"name":"CISA KEV: Gitea CVE-2026-60004 RCE + Related CVE-2026-20896 Exploitation","url":"https://otx.alienvault.com/pulse/6a966b36e05073e4e9f59da0","created":"2026-09-01"},{"name":"Gitea CVE-2026-60004 Diffpatch RCE — CISA KEV Active Exploitation","url":"https://otx.alienvault.com/pulse/6a9519a0f2700898dcfac313","created":"2026-08-31"},{"name":"Gitea CVE-2026-60004 Active RCE + Docker Auth Bypass CVE-2026-20896","url":"https://otx.alienvault.com/pulse/6a92768c6122e56489c00a80","created":"2026-08-29"},{"name":"CVE-2026-8452 Citrix NetScaler Pre-Auth RCE Exploited (CISA KEV)","url":"https://otx.alienvault.com/pulse/6a8fd35dd83c195e8a57a121","created":"2026-08-27"},{"name":"CISA KEV: CVE-2026-21962 Oracle WebLogic/HTTP Server Proxy RCE","url":"https://otx.alienvault.com/pulse/6a8e81f720592a8fa12e209a","created":"2026-08-26"},{"name":"Gitea CVE-2026-59774: Unauth Org-Mode File Read to Possible RCE","url":"https://otx.alienvault.com/pulse/6a82a48175100560f3fdd2b3","created":"2026-08-17"},{"name":"Known_Cve | Jul 5, 2026 | Part 2/2","url":"https://otx.alienvault.com/pulse/6a49158e8744b9c06c495b6f","created":"2026-07-04"}],"provenance":"machine"},"cwes":[{"id":"CWE-284","name":"Improper Access Control"}],"references":[{"url":"https://github.com/go-gitea/gitea/security/advisories/GHSA-f75j-4cw6-rmx4","tags":["vendor-advisory"]},{"url":"https://github.com/go-gitea/gitea/pull/38151","tags":["patch"]},{"url":"https://github.com/go-gitea/gitea/releases/tag/v1.26.3","tags":["release-notes"]},{"url":"https://blog.gitea.com/release-of-1.26.3-and-1.26.4/","tags":["release-notes"]}],"techniques":[],"reports":[],"affected":[{"ecosystem":"Go","package":"code.gitea.io/gitea","vulnerableRanges":["<1.26.3"],"patched":["1.26.3"],"from":["GHSA-f75j-4cw6-rmx4","GO-2026-6051"],"provenance":"source"}],"advisories":[{"id":"GHSA-f75j-4cw6-rmx4","url":"https://github.com/advisories/GHSA-f75j-4cw6-rmx4","severity":"CRITICAL","ecosystem":"Go","package":"code.gitea.io/gitea","vulnerableRanges":["<1.26.3"],"patched":["1.26.3"],"provenance":"source","from":"GHSA"}],"euvd":{"id":"EUVD-2026-41614","url":"https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-41614","exploited":false,"exploitedSince":null,"provenance":"source"},"exploits":[],"exploitSources":{"pocGithub":{"count":8,"skipped":0,"earliest":"2026-07-02","earliestUrl":"https://github.com/kaleth4/CVE-2026-20896","repos":[{"name":"szybnev/cve-2026-20896-gitea-poc","url":"https://github.com/szybnev/cve-2026-20896-gitea-poc","stars":10,"created":"2026-07-07"},{"name":"rz1027/CVE-2026-20896","url":"https://github.com/rz1027/CVE-2026-20896","stars":6,"created":"2026-07-05"},{"name":"XaocZenon/CVE-2026-20896","url":"https://github.com/XaocZenon/CVE-2026-20896","stars":6,"created":"2026-07-16"},{"name":"kaleth4/CVE-2026-20896","url":"https://github.com/kaleth4/CVE-2026-20896","stars":1,"created":"2026-07-02"},{"name":"EQSTLab/CVE-2026-20896","url":"https://github.com/EQSTLab/CVE-2026-20896","stars":1,"created":"2026-07-29"}]},"nuclei":[{"id":"CVE-2026-20896","name":"Gitea Docker Image <= 1.26.2 - Reverse Proxy Header Authentication Bypass","severity":"critical","path":"http/cves/2026/CVE-2026-20896.yaml","url":"https://github.com/projectdiscovery/nuclei-templates/blob/main/http/cves/2026/CVE-2026-20896.yaml"}],"first":{"date":"2026-07-02","source":"PoC-in-GitHub","url":"https://github.com/kaleth4/CVE-2026-20896"},"provenance":"source"},"exploitRefs":[],"flow":[],"timeline":[{"date":"2026-07-02","kind":"exploit-public","label":"First public exploit: PoC-in-GitHub","url":"https://github.com/kaleth4/CVE-2026-20896","provenance":"source"},{"date":"2026-07-03","kind":"published","label":"Published (CVE.org)","url":"https://www.cve.org/CVERecord?id=CVE-2026-20896","provenance":"source"},{"date":"2026-07-06","kind":"exploited-reported","label":"Exploitation first reported (VulnCheck KEV evidence)","url":"https://www.linkedin.com/feed/update/urn:li:activity:7479652557561454592/","provenance":"source"}],"speed":{"daysToPublicExploit":null,"firstExploitFrom":"PoC-in-GitHub","daysToKev":null},"priority":{"score":71.4,"factors":[{"name":"In a KEV catalog","points":35.0,"detail":"listed in VulnCheck KEV"},{"name":"Recent KEV listing","points":5.0,"detail":"added 117 days ago"},{"name":"Known ransomware use","points":0.0,"detail":"not known"},{"name":"EPSS percentile","points":17.24,"detail":"percentile 0.8622"},{"name":"Named in threat reports","points":0.0,"detail":"0 reports"},{"name":"Public exploit code","points":5.0,"detail":"8 PoC-in-GitHub repos; 1 nuclei template"},{"name":"Mentioned in OTX pulses","points":2.27,"detail":"9 pulses"},{"name":"CVSS severity","points":6.86,"detail":"base score 9.8"},{"name":"End-of-life product","points":0.0,"detail":"supported or unknown"}]}}