SeaweedFS: Unauthenticated filer IAM gRPC service grants S3 administrative control

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

9.8 · CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS

• CVE-2026-72920: 0.78% estimated exploitation activity in the next 30 days; percentile 55.95 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Impact The 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. No 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 allowedcommonNames ACL applies to the port rather than to individual RPCs, so any cluster mesh certificate could reach these administrative calls. Affected component - weed/server/filerserverhandlersiamgrpc.go - weed/command/filer.go Patches Fixed in 4.24. Every IAM RPC now requires a Bearer token signed with the filer admin signing key (jwt.filersigning.key), and the service refuses to register when no signing…

Published by the source

2 Sep 2026, 14:51 UTC

Last modified by the source

10 Sep 2026, 15:26 UTC

Source last checked

26 Oct 2026, 15:28 UTC

1. Revision 3 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-2v6v-25fm-p4fg

2. Revision 2 · amended · 24 Oct 2026

   Amended from osv record GO-2026-6351

3. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-2v6v-25fm-p4fg

Preview the exact text before you copy it. Commands are read-only suggestions; review them before running anything.

# Patch Next advisory brief: CVE-2026-72920

Advisory: SeaweedFS: Unauthenticated filer IAM gRPC service grants S3 administrative control
IDs: CVE-2026-72920, GHSA-2v6v-25fm-p4fg
Record: https://patchnext.com/advisories/cve-2026-72920 (revision 3, source checked 26 Oct 2026, 15:28 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Critical (CVSS 9.8)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: github.com/seaweedfs/seaweedfs 0.0.0-20260512171108-5e8f99f40a8a. A vendor fix does not mean a deployment is fixed.

## Affected components
- Go github.com/seaweedfs/seaweedfs: affected < 0.0.0-20260512171108-5e8f99f40a8a; fixed in 0.0.0-20260512171108-5e8f99f40a8a

## Suggested inspection (read-only)
- Go github.com/seaweedfs/seaweedfs: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on github.com/seaweedfs/seaweedfs.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://osv.dev/vulnerability/GHSA-2v6v-25fm-p4fg (OSV record GHSA-2v6v-25fm-p4fg lists affected ranges: Go github.com/seaweedfs/seaweedfs >=0 <0.0.0-20260512171108-5e8f99f40a8a (fixed))
- Verified: https://osv.dev/vulnerability/GO-2026-6351 (OSV record GO-2026-6351 lists affected ranges: Go github.com/seaweedfs/seaweedfs >=0 <0.0.0-20260512171108-5e8f99f40a8a (fixed))
- Verified: https://github.com/advisories/GHSA-2v6v-25fm-p4fg (GitHub-reviewed advisory GHSA-2v6v-25fm-p4fg lists affected ranges: Go github.com/seaweedfs/seaweedfs >=0 <0.0.0-20260512171108-5e8f99f40a8a)

Commands are suggestions: review each one before running it.