How severe is CVE-2026-72920?

CVE-2026-72920 has a CVSS score of 9.8/10, rated CRITICAL. Immediate patching is strongly recommended.

Which packages are affected by CVE-2026-72920?

CVE-2026-72920 affects the following packages: github.com/seaweedfs/seaweedfs (Go). Ecosystems affected: Go.

How do I fix CVE-2026-72920?

Update github.com/seaweedfs/seaweedfs to 0.0.0-20260512171108-5e8f99f40a8a or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-72920 is resolved across your whole dependency graph.

How do I detect CVE-2026-72920 in my Go dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/seaweedfs/seaweedfs, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2026-72920 if there is no patch (or I can't update yet)?

Put an independent control in front of the weakness: restrict the affected endpoint or interface to trusted networks, require an additional authentication factor or proxy-level check, and invalidate existing sessions and credentials in case the flaw has already been used.

Is CVE-2026-72920 actively exploited in the wild?

No public exploit code has been indexed for CVE-2026-72920 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2026-72920?

CVE-2026-72920 has an EPSS (Exploit Prediction Scoring System) score of 0.8%, placing it in the 54th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2026-72920?

CVE-2026-72920 is classified as Missing Authentication (CWE-306). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2026-72920 published, and has it been updated?

CVE-2026-72920 was published on August 11, 2026 and was last updated on September 27, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🐹

🐹 Go

Not in CISA KEV

CRITICAL severity

CVE-2026-72920 — seaweedfs

CRITICALFix: seaweedfs/seaweedfs@5e8f99f

CVE-2026-72920 is a critical-severity (CVSS 9.8) Missing Authentication vulnerability in github.com/seaweedfs/seaweedfs. A fix is available for github.com/seaweedfs/seaweedfs — see the affected versions and patch details below.

SeaweedFS: Unauthenticated filer IAM gRPC service grants S3 administrative control

Also known asBIT-seaweedfs-2026-72920GHSA-2v6v-25fm-p4fgGO-2026-6351

Published

Aug 11, 2026

Updated

Sep 27, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Oct 6, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
A successful exploit gives an attacker total control of the affected component, not partial access.
CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for CVE-2026-72920.

EPSS Exploitation Probability

via FIRST.org ↗

0.8%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs54th percentile — riskier than 54% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

CVE-2026-72920 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.

Where this sits among everything scored

Of 383,485 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.

Real-World Exposure

1 pkg affected

🐹github.com/seaweedfs/seaweedfs

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.

Description

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 allowed_commonNames ACL applies to the port rather than to individual RPCs, so any cluster mesh certificate could reach these administrative calls.

Affected component

weed/server/filer_server_handlers_iam_grpc.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.filer_signing.key), and the service refuses to register when no signing key is configured — removing the unauthenticated default entirely.

Workarounds

Restrict 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.

References

Fixed by seaweedfs/seaweedfs#9442 (follow-ups: #9498, #9508, #9514, #9536)
Reported by Kadir Arslan (https://github.com/KadirArslan)

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
🐹Go	`github.com/seaweedfs/seaweedfs`	all versions	0.0.0-20260512171108-5e8f99f40a8a`go get github.com/seaweedfs/seaweedfs@v0.0.0-20260512171108-5e8f99f40a8a`

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/seaweedfs/seaweedfs, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update github.com/seaweedfs/seaweedfs to 0.0.0-20260512171108-5e8f99f40a8a or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-72920 is resolved across your whole dependency graph.
Workarounds
Put an independent control in front of the weakness: restrict the affected endpoint or interface to trusted networks, require an additional authentication factor or proxy-level check, and invalidate existing sessions and credentials in case the flaw has already been used.

Frequently Asked Questions

### 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 `allow