{"document":{"category":"csaf_vex","csaf_version":"2.0","title":"CVE-2026-20896: Gitea Docker image trusts spoofable reverse-proxy headers by default","publisher":{"category":"vendor","name":"HarborGuard Database","namespace":"https://database.harborguard.co"},"tracking":{"id":"CVE-2026-20896","status":"final","version":"1","initial_release_date":"2026-07-03T20:19:29.588Z","current_release_date":"2026-07-03T20:19:29.588Z","revision_history":[{"date":"2026-07-03T20:19:29.588Z","number":"1","summary":"Initial machine-readable export from HarborGuard."}]},"distribution":{"tlp":{"label":"WHITE"},"text":"Public CVE data; freely redistributable."},"notes":[{"category":"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.","title":"CVE description"}],"references":[{"category":"self","summary":"CVE-2026-20896 on HarborGuard Database","url":"https://database.harborguard.co/cve/CVE-2026-20896"},{"category":"external","summary":"CVE Record","url":"https://www.cve.org/CVERecord?id=CVE-2026-20896"},{"category":"external","summary":"GitHub Security Advisory","url":"https://github.com/go-gitea/gitea/security/advisories/GHSA-f75j-4cw6-rmx4"},{"category":"external","summary":"GitHub Pull Request #38151","url":"https://github.com/go-gitea/gitea/pull/38151"},{"category":"external","summary":"Gitea v1.26.3 Release","url":"https://github.com/go-gitea/gitea/releases/tag/v1.26.3"},{"category":"external","summary":"Gitea v1.26.4 Release Blog Post","url":"https://blog.gitea.com/release-of-1.26.3-and-1.26.4/"}]},"product_tree":{"branches":[{"category":"vendor","name":"Gitea","branches":[{"category":"product_name","name":"Gitea Open Source Git Server","branches":[{"category":"product_version_range","name":"<=1.26.2","product":{"name":"Gitea Gitea Open Source Git Server <=1.26.2","product_id":"CSAFPID-1","product_identification_helper":{"cpe":"cpe:2.3:a:gitea:gitea_open_source_git_server:*:*:*:*:*:*:*:*"}}}]}]}]},"vulnerabilities":[{"cve":"CVE-2026-20896","title":"Gitea Docker image trusts spoofable reverse-proxy headers by default","notes":[{"category":"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.","title":"CVE description"}],"product_status":{"known_affected":["CSAFPID-1"]},"scores":[{"cvss_v3":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","baseScore":9.8,"baseSeverity":"CRITICAL"},"products":["CSAFPID-1"]}],"remediations":[{"category":"none_available","details":"No fixed version is published yet. Monitor the upstream advisory.","product_ids":["CSAFPID-1"]}]}]}