CVE-2026-54089File Browser: Authentication Bypass via Proxy Auth Header Forgery
- 9.1CriticalCVSS base score
- 0.61%Exploitation in 30 daysEPSS · top 50% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- YesPublic exploitsa reference or SSVC says so
Description
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.
Public exploit
An exploit or proof of concept is public: anyone can try it against an unpatched system. A reference of the record is tagged as an exploit. CISA's SSVC rates its exploitation: a proof of concept is public.
Show the exploits1
References tagged exploit1 reference
- https://github.com/filebrowser/filebrowser/security/advisories/GHSA-xqp3-jq6g-x3qm (opens in a new tab)x_refsource_CONFIRMexploit
Timeline
ID reserved
By GitHub_M
- 14 days later
· 14 days later
Published
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| GitHub_MCNA (assigner) | 3.1 | Critical9.1 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N |
| NVDNVD · Deferred | 3.1 | Critical9.1 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N |
- EPSS (exploitation in 30 days)
- 0.61% · top 50% of all CVEs (14 Nov 2026)
- CISA SSVC
- Exploitation: poc · Automatable: yes · Technical impact: total
The list uses the assigner's score when there is one, then CISA's, then NVD's: Critical 9.1.
Affected products
- affected >= 2.0.0-rc.1
Affected packages
From reviewed advisories of the GitHub Advisory Database.
- Gogithub.com/filebrowser/filebrowser/v2GHSA-xqp3-jq6g-x3qm (opens in a new tab)
References
References3
- https://github.com/filebrowser/filebrowser/security/advisories/GHSA-xqp3-jq6g-x3qm (opens in a new tab)x_refsource_CONFIRMexploit
- https://github.com/filebrowser/filebrowser/blob/main/auth/proxy.go (opens in a new tab)x_refsource_MISC
- https://github.com/filebrowser/filebrowser/blob/main/http/auth.go#L121-L137 (opens in a new tab)x_refsource_MISC
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2026-39508 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisory GHSA-xqp3-jq6g-x3qm (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2026-54089)Record last updated .