GHSA-gv5w-hfx8-8cwq
SeaweedFS: Filer JWT allowed_prefixes literal prefix match allows cross-tenant access to sibling paths
Packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| Go | github.com/seaweedfs/seaweedfs | < 0.0.0-20260512171048-05ed5c9ae8a2 | 0.0.0-20260512171048-05ed5c9ae8a2 |
Details
As written in the advisory (Markdown source, shown as plain text).
### Impact
When a filer JWT restricts a token to a set of path prefixes via `allowed_prefixes`, the authorization check used a literal byte-prefix match (`strings.HasPrefix`). A token scoped to `/tenant1` therefore also authorized requests to sibling paths such as `/tenant1234`, `/tenant1-old`, and `/tenant1backup`.
In a multi-tenant deployment this lets the holder of one tenant's token access another tenant's data. Because `allowed_prefixes` gates both read and write tokens, the impact covers cross-tenant reads and writes. A valid scoped token is required, so this is an authorization bypass rather than a fully unauthenticated flaw.
### Affected component
- `weed/server/filer_server_handlers.go` (JWT `allowed_prefixes` authorization check)
### Patches
Fixed in **4.24**. The check now matches on `/`-separated path components after `path.Clean` normalisation, so `/tenant1` authorizes only `/tenant1` and its descendants — not `/tenant1234` or other sibling paths.
### Workarounds
Where feasible, choose prefix names that are not string-prefixes of one another (e.g. keep a trailing separator convention). Upgrade to 4.24.
### References
- Reported by Kadir Arslan (https://github.com/KadirArslan)
References
External links from the advisory. They lead to third-party sites.
- https://github.com/seaweedfs/seaweedfs/security/advisories/GHSA-gv5w-hfx8-8cwq
- https://nvd.nist.gov/vuln/detail/CVE-2026-72921
- https://github.com/seaweedfs/seaweedfs/pull/9439
- https://github.com/seaweedfs/seaweedfs/commit/05ed5c9ae8a2a45101b52b61d02f170d20d587ff
- https://github.com/seaweedfs/seaweedfs
- https://github.com/seaweedfs/seaweedfs/releases/tag/4.24