CVE-2026-54917: SeaweedFS: Path traversal in the S3 and Iceberg REST gateways allows cross-bucket access

Severity: critical (CVSS 10.0 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 1.6% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2026-06-25 · updated 2026-06-29
Weakness: CWE-22

Description

SeaweedFS is a distributed storage system for object storage (S3), file systems, and Iceberg tables. Prior to 4.30, the S3 API gateway and the Iceberg REST catalog gateway construct their routers with mux.NewRouter().SkipClean(true). With path cleaning disabled, a .. segment inside the URL survives routing, so a request such as `GET /bucket-A/../evil-bucket/key`, is matched as bucket=bucket-A, object=../evil-bucket/key. The captured object key is then joined into a filer path with util.JoinPath (S3) / path.Join (Iceberg), which collapse the .. server-side, so the actual read or write lands in evil-bucket. This vulnerability is fixed in 4.30.

Affected products

seaweedfs: before 4.30 — fixed in 4.30

How to fix

Upgrade to a fixed version: seaweedfs 4.30. Check the vendor advisory for mitigations.

References

Get alerted when CVE-2026-54917 or the next vulnerability affects your stack