{"document":{"category":"csaf_vex","csaf_version":"2.0","title":"CVE-2026-54089: File Browser: Authentication Bypass via Proxy Auth Header Forgery","publisher":{"category":"vendor","name":"HarborGuard Database","namespace":"https://database.harborguard.co"},"tracking":{"id":"CVE-2026-54089","status":"final","version":"1","initial_release_date":"2026-06-25T17:46:13.119Z","current_release_date":"2026-06-25T18:33:37.531Z","revision_history":[{"date":"2026-06-25T17:46:13.119Z","number":"1","summary":"Initial machine-readable export from HarborGuard."}]},"distribution":{"tlp":{"label":"WHITE"},"text":"Public CVE data; freely redistributable."},"notes":[{"category":"description","text":"File Browser is a file managing interface for uploading, deleting, previewing, renaming, and editing files within a specified directory. Starting with 2.0.0-rc.1, when FileBrowser is configured with proxy authentication (auth.method=proxy), any unauthenticated attacker who can reach the server directly can impersonate any user - including admin - by sending a single forged HTTP header. No credentials are required. Additionally, specifying a non-existent username causes the server to automatically create a new user account, providing an account creation primitive with no authorization. This is an already known issue that has been documented in the documentation for several years, but has not been documented as a vulnerability before.","title":"CVE description"}],"references":[{"category":"self","summary":"CVE-2026-54089 on HarborGuard Database","url":"https://database.harborguard.co/cve/CVE-2026-54089"},{"category":"external","summary":"CVE Record","url":"https://www.cve.org/CVERecord?id=CVE-2026-54089"},{"category":"external","summary":"https://github.com/filebrowser/filebrowser/security/advisories/GHSA-xqp3-jq6g-x3qm","url":"https://github.com/filebrowser/filebrowser/security/advisories/GHSA-xqp3-jq6g-x3qm"},{"category":"external","summary":"https://github.com/filebrowser/filebrowser/blob/main/auth/proxy.go","url":"https://github.com/filebrowser/filebrowser/blob/main/auth/proxy.go"},{"category":"external","summary":"https://github.com/filebrowser/filebrowser/blob/main/http/auth.go#L121-L137","url":"https://github.com/filebrowser/filebrowser/blob/main/http/auth.go#L121-L137"}]},"product_tree":{"branches":[{"category":"vendor","name":"filebrowser","branches":[{"category":"product_name","name":"filebrowser","branches":[{"category":"product_version","name":">= 2.0.0-rc.1","product":{"name":"filebrowser filebrowser >= 2.0.0-rc.1","product_id":"CSAFPID-1","product_identification_helper":{"cpe":"cpe:2.3:a:filebrowser:filebrowser:\\>\\=_2.0.0-rc.1:*:*:*:*:*:*:*"}}}]}]}]},"vulnerabilities":[{"cve":"CVE-2026-54089","title":"File Browser: Authentication Bypass via Proxy Auth Header Forgery","notes":[{"category":"description","text":"File Browser is a file managing interface for uploading, deleting, previewing, renaming, and editing files within a specified directory. Starting with 2.0.0-rc.1, when FileBrowser is configured with proxy authentication (auth.method=proxy), any unauthenticated attacker who can reach the server directly can impersonate any user - including admin - by sending a single forged HTTP header. No credentials are required. Additionally, specifying a non-existent username causes the server to automatically create a new user account, providing an account creation primitive with no authorization. This is an already known issue that has been documented in the documentation for several years, but has not been documented as a vulnerability before.","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:N","baseScore":9.1,"baseSeverity":"CRITICAL"},"products":["CSAFPID-1"]}],"remediations":[{"category":"none_available","details":"No fixed version is published yet. Monitor the upstream advisory.","product_ids":["CSAFPID-1"]}]}]}