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

Source

https://github.com/projectdiscovery/nuclei-templates/blob/main/http/cves/2026/CVE-2026-54917.yaml

Associated Vulnerability

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

Description

SeaweedFS versions through 4.29 build the S3 API and Iceberg REST catalog routers with mux.NewRouter().SkipClean(true), which disables URL path cleaning. A `..` segment in the request path therefore survives routing and reaches the handlers unnormalised, so a request such as `PUT /bucket-A/../evil-bucket/key` is matched as bucket=bucket-A with object=../evil-bucket/key. The captured object key is then joined into a filer path where the `..` is collapsed server-side, so the write lands in evil-bucket while authorisation is evaluated against bucket-A, enabling cross-bucket file write.

File Snapshot

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