GitHub Advisoryadvisory · Go

GHSA-gv5w-hfx8-8cwq SeaweedFS: Filer JWT allowed_prefixes literal prefix match allows cross-tenant access to sibling paths

HIGH Published 2026-09-02 Modified 2026-09-02 Official page ↗
Aliases
CVE-2026-72921
Ecosystem
Go
Packages
github.com/seaweedfs/seaweedfs
Severity
High
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
Weaknesses
CWE-863
Reviewed
2026-09-02

Affected packages

• Go github.com/seaweedfs/seaweedfs: < 0.0.0-20260512171048-05ed5c9ae8a2 → fixed in 0.0.0-20260512171048-05ed5c9ae8a2

Description

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)

Related

Alias · CVE (1)

  • CVE-2026-72921 SeaweedFS is a distributed storage system. vulnerability

Weakness · CWE (1)

  • CWE-863 Incorrect Authorization weakness

References