CVE-2026-72920: SeaweedFS Unauthenticated Filer IAM GRPC Service Vulnerability
CRITICALCVE-2026-72920 is a CRITICAL (CVSS 9.8) unauthenticated filer iam grpc service vulnerability (CWE-306: Missing Authentication for Critical Function) affecting SeaweedFS libraries in the Go ecosystem. The issue involves unauthenticated filer iam grpc service grants s3 administrative control. Remediation is available by upgrading affected packages to version 0.0.0-20260512171108-5e8f99f40a8a.
CVE-2026-72920 at a Glance
Security Impact
CVSS: 9.8
The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H).
How to Fix CVE-2026-72920
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 0.0.0-20260512171108-5e8f99f40a8aRun 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-2026-72920, 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 0.0.0-20260512171108-5e8f99f40a8a), 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-306: Missing Authentication for Critical Function, where the product does not perform any authentication for functionality that requires a provable user identity or consumes a significant amount of resources. 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-2026-72920 Affected SeaweedFS Versions
1 component(s)| Product / Package | Ecosystem | Affected Versions | Fixed Version |
|---|---|---|---|
|
github.com/seaweedfs/seaweedfs
|
Go |
< 0.0.0-20260512171108-5e8f99f40a8a
|
0.0.0-20260512171108-5e8f99f40a8a
|
References
Frequently Asked Questions
What is CVE-2026-72920?
Which SeaweedFS versions are affected?
What version fixes CVE-2026-72920?
Is github.com/seaweedfs/seaweedfs affected?
What is the CVSS score of CVE-2026-72920?
What CWE is associated with CVE-2026-72920?
How can I check Go dependencies for CVE-2026-72920?
Machine-readable OSV JSON
OSV v1.5 Schema
{
"schema_version" : "1.4.0",
"id" : "GHSA-2v6v-25fm-p4fg",
"modified" : "2026-09-02T14:51:59Z",
"published" : "2026-09-02T14:51:58Z",
"aliases" : [ "CVE-2026-72920" ],
"summary" : "SeaweedFS: Unauthenticated filer IAM gRPC service grants S3 administrative control",
"details" : "### Impact\nThe filer registered the IAM gRPC service (`SeaweedIdentityAccessManagement`) with no authentication. Any client able to reach the filer gRPC port could invoke IAM RPCs — `CreateUser`, `CreateAccessKey`, `PutUserPolicy`, and related calls — to mint credentials and grant itself S3 administrative privileges. This fully compromises the confidentiality, integrity, and availability of stored objects.\n\nNo credentials are required, and enabling the documented JWT signing keys does not close it: the IAM gRPC service was not gated by that mechanism. Even under mTLS, the listener-level `allowed_commonNames` ACL applies to the port rather than to individual RPCs, so any cluster mesh certificate could reach these administrative calls.\n\n### Affected component\n- `weed/server/filer_server_handlers_iam_grpc.go`\n- `weed/command/filer.go`\n\n### Patches\nFixed in **4.24**. Every IAM RPC now requires a Bearer token signed with the filer admin signing key (`jwt.filer_signing.key`), and the service refuses to register when no signing key is configured — removing the unauthenticated default entirely.\n\n### Workarounds\nRestrict the filer gRPC port to trusted hosts. Configure `jwt.filer_signing.key` in `security.toml` and upgrade to 4.24; operators that use the IAM RPCs must attach an admin-signed Bearer token on each call.\n\n### References\n- Fixed by seaweedfs/seaweedfs#9442 (follow-ups: #9498, #9508, #9514, #9536)\n- Reported by Kadir Arslan (https://github.com/KadirArslan)",
"severity" : [ {
"type" : "CVSS_V3",
"score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"
} ],
"affected" : [ {
"package" : {
"ecosystem" : "Go",
"name" : "github.com/seaweedfs/seaweedfs"
},
"ranges" : [ {
"type" : "ECOSYSTEM",
"events" : [ {
"introduced" : "0"
}, {
"fixed" : "0.0.0-20260512171108-5e8f99f40a8a"
} ]
} ]
} ],
"references" : [ {
"type" : "WEB",
"url" : "https://github.com/seaweedfs/seaweedfs/security/advisories/GHSA-2v6v-25fm-p4fg"
}, {
"type" : "ADVISORY",
"url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-72920"
}, {
"type" : "WEB",
"url" : "https://github.com/seaweedfs/seaweedfs/pull/9442"
}, {
"type" : "WEB",
"url" : "https://github.com/seaweedfs/seaweedfs/commit/5e8f99f40a8abc7b449aefd260516443377041c7"
}, {
"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-306" ],
"severity" : "CRITICAL",
"github_reviewed" : true,
"github_reviewed_at" : "2026-09-02T14:51:58Z",
"nvd_published_at" : "2026-08-11T15:17:38Z"
}
}