CVE-2026-72921: SeaweedFS Filer JWT Allowed_prefixes Literal Prefix Vulnerability
HIGHCVE-2026-72921 is a HIGH (CVSS 8.1) filer jwt allowed_prefixes literal prefix vulnerability (CWE-863: Incorrect Authorization) affecting SeaweedFS libraries in the Go ecosystem. The issue involves filer jwt allowed_prefixes literal prefix match allows cross-tenant access to sibling paths. Remediation is available by upgrading affected packages to version 0.0.0-20260512171048-05ed5c9ae8a2.
CVE-2026-72921 at a Glance
Security Impact
CVSS: 8.1
The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N).
How to Fix CVE-2026-72921
To remediate this vulnerability, upgrade all affected SeaweedFS dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.
Upgrade github.com/seaweedfs/seaweedfs to 0.0.0-20260512171048-05ed5c9ae8a2Run the following command in your project directory to verify that all resolved dependencies use the patched release:
inspect dependencies for github.com/seaweedfs/seaweedfsHow to Check if You Are Affected
To determine whether your application is affected by CVE-2026-72921, inspect your project dependencies for SeaweedFS:
inspect dependencies for github.com/seaweedfs/seaweedfsAnalyze the terminal output to locate any version of SeaweedFS in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 0.0.0-20260512171048-05ed5c9ae8a2), your application is affected.
Note: Verify declared build manifests and deployed runtime container environments.
Technical Details
Vulnerability Mechanism & Technical Analysis
This vulnerability is classified under CWE-863: Incorrect Authorization, where the product performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the check. In SeaweedFS, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.
Source Advisory Statement
CVE-2026-72921 Affected SeaweedFS Versions
1 component(s)| Product / Package | Ecosystem | Affected Versions | Fixed Version |
|---|---|---|---|
|
github.com/seaweedfs/seaweedfs
|
Go |
< 0.0.0-20260512171048-05ed5c9ae8a2
|
0.0.0-20260512171048-05ed5c9ae8a2
|
References
Frequently Asked Questions
What is CVE-2026-72921?
Which SeaweedFS versions are affected?
What version fixes CVE-2026-72921?
Is github.com/seaweedfs/seaweedfs affected?
What is the CVSS score of CVE-2026-72921?
What CWE is associated with CVE-2026-72921?
How can I check Go dependencies for CVE-2026-72921?
Machine-readable OSV JSON
OSV v1.5 Schema
{
"schema_version" : "1.4.0",
"id" : "GHSA-gv5w-hfx8-8cwq",
"modified" : "2026-09-02T23:42:05Z",
"published" : "2026-09-02T23:42:05Z",
"aliases" : [ "CVE-2026-72921" ],
"summary" : "SeaweedFS: Filer JWT allowed_prefixes literal prefix match allows cross-tenant access to sibling paths",
"details" : "### Impact\nWhen 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`.\n\nIn 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.\n\n### Affected component\n- `weed/server/filer_server_handlers.go` (JWT `allowed_prefixes` authorization check)\n\n### Patches\nFixed 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.\n\n### Workarounds\nWhere feasible, choose prefix names that are not string-prefixes of one another (e.g. keep a trailing separator convention). Upgrade to 4.24.\n\n### References\n- Reported by Kadir Arslan (https://github.com/KadirArslan)",
"severity" : [ {
"type" : "CVSS_V3",
"score" : "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N"
} ],
"affected" : [ {
"package" : {
"ecosystem" : "Go",
"name" : "github.com/seaweedfs/seaweedfs"
},
"ranges" : [ {
"type" : "ECOSYSTEM",
"events" : [ {
"introduced" : "0"
}, {
"fixed" : "0.0.0-20260512171048-05ed5c9ae8a2"
} ]
} ]
} ],
"references" : [ {
"type" : "WEB",
"url" : "https://github.com/seaweedfs/seaweedfs/security/advisories/GHSA-gv5w-hfx8-8cwq"
}, {
"type" : "ADVISORY",
"url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-72921"
}, {
"type" : "WEB",
"url" : "https://github.com/seaweedfs/seaweedfs/pull/9439"
}, {
"type" : "WEB",
"url" : "https://github.com/seaweedfs/seaweedfs/commit/05ed5c9ae8a2a45101b52b61d02f170d20d587ff"
}, {
"type" : "PACKAGE",
"url" : "https://github.com/seaweedfs/seaweedfs"
}, {
"type" : "WEB",
"url" : "https://github.com/seaweedfs/seaweedfs/releases/tag/4.24"
} ],
"database_specific" : {
"cwe_ids" : [ "CWE-863" ],
"severity" : "HIGH",
"github_reviewed" : true,
"github_reviewed_at" : "2026-09-02T23:42:05Z",
"nvd_published_at" : "2026-08-11T15:17:38Z"
}
}