Authorization Flaw in github.com/filebrowser/filebrowser/v2 (CVE-2026-54091)
Summary
Vulnerability in github.com/filebrowser/filebrowser/v2 (CVE-2026-54091). Confidential information can be exposed externally. Exploitable via GET /api/public/share/. Mitigation: upgrade to 2.63.6 or later.
Original description
The description as published by the source.
File Browser is a file managing interface for uploading, deleting, previewing, renaming, and editing files within a specified directory. Prior to 2.63.6, File Browser's public share handlers rebase the share owner's filesystem root to the shared directory and then evaluate descendant paths against the owner's global and per-user rules using the rebased relative path instead of the original path relative to the owner's scope. As a result, an attacker who knows a public directory share URL can access files and subdirectories that the owner explicitly blocked with rules, as long as those blocked paths are located underneath the shared directory. In the simplest case this is an unauthenticated information disclosure through GET /api/public/share/* and GET /api/public/dl/*. This vulnerability is fixed in 2.63.6.
Source: GitHub Security Advisories (Global) NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-54091 has been found in github.com/filebrowser/filebrowser/v2.
Attackers can target a specific entry point like GET /api/public/share/ over the network to misuse the product.
Confidential information can be exposed externally. CVSS score: 7.5/10.
What to do: upgrade github.com/filebrowser/filebrowser/v2 to 2.63.6 or later.
If unsure, ask your IT team or search "github.com/filebrowser/filebrowser/v2 CVE-2026-54091" on the vendor's site.
CVE-2026-54091 (github.com/filebrowser/filebrowser/v2) — CWE-863 / CVSS v3 7.5
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Attack surface: GET /api/public/share/ / GET /api/public/dl/ / d.user.Fs / BasePathFs
Patched: 2.63.6 — apply immediately
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
Incorrect authorization (CWE-863) exists in github.com/filebrowser/filebrowser/v2. Attackers reach the vulnerable code path via GET /api/public/share/ without authentication.
Check the vendor advisory for the affected versions of github.com/filebrowser/filebrowser/v2. Attack surface: GET /api/public/share/ / GET /api/public/dl/ / d.user.Fs / BasePathFs.
Severity: High (CVSS 7.5/10). Confidential information can be exposed externally.
Update to 2.63.6.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual GET /api/public/share/ requests with malformed payloads or SQL meta-characters. Run grep -r 'github.com/filebrowser/filebrowser/v2' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify exposure identify
grep -r 'github.com/filebrowser/filebrowser/v2' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
github.com/filebrowser/filebrowser/v2を grep し、稼働しているサービス・バージョンを把握する。 -
2Hunt for indicators of compromise detect
grep 'GET /api/public/share/' /var/log/nginx/access.log | grep -E '(unusual_payload|sqli_pattern)'アクセスログで
GET /api/public/share/への異常なリクエスト (不正な認証ヘッダ・SQLメタ文字)を過去 30〜90日分捜索。WAF/SIEM があれば該当パスのアラート発火履歴を確認。 -
3Apply patch patch
Upgrade github.com/filebrowser/filebrowser/v2 to 2.63.6ステージング環境で 2.63.6 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスと、Step 2 で見つけた異常検知の続報チェックを含めること。
-
4Post-deployment verification verify
Replay attack against GET /api/public/share/ on staging to confirm patch closes the vectorパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番では Step 2 と同じログクエリでアラート再発が無いか継続監視。
Affected packages
References
- advisory github.com
- advisory nvd.nist.gov
- advisory github.com
- package github.com
- patch github.com
- web github.com
- web github.com