CVE-2026-77611: high-severity vulnerability in seaweedfs
SeaweedFS: Authenticated S3 object-scope bypass in PutObjectAcl allows overwriting a different object with the same basename
Published · Updated
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21Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 7.1epss 0.4%
SeaweedFS is a distributed storage system for files and blobs. In versions prior to 4.40, an authenticated S3 principal with permissions scoped to a nested object key can overwrite a different object outside that scope by calling PutObjectAcl on the key it is allowed to access. The handler authorizes the request against the requested nested key but then writes the updated entry back to the bucket root rather than the key's actual parent directory, so an ACL change on allowed/protected.txt is instead applied to protected.txt at the bucket root. Because the update carries the full entry rather than only ACL metadata, an existing target object is overwritten with the content, metadata, owner information, and ACL of the scoped object, bypassing the object-level action scoping configured through the static S3 identity file. This issue is fixed in version 4.40.
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:L
Affected products
seaweedfs · seaweedfsRelated CVEs — seaweedfs
In the same product, most dangerous first.
CVE-2026-54917HIGHSeaweedFS: Path traversal in the S3 and Iceberg REST gateways allows cross-bucket accessEPSS 1.6%CVE-2026-58372HIGHSeaweedFS < 4.34 - Cross-Bucket Object Deletion via DeleteObjects Request-Body KeysEPSS 0.9%CVE-2026-72920CRITICALSeaweedFS: Unauthenticated filer IAM gRPC service grants S3 administrative controlEPSS 0.8%CVE-2026-55874HIGHSeaweedFS: Path traversal in the S3 gateway X-Amz-Copy-Source header allows cross-bucket object readEPSS 0.6%CVE-2026-73080CRITICALSeaweedFS: Unauthenticated SSRF with response read-back via VolumeServer.FetchAndWriteNeedleEPSS 0.5%CVE-2026-72921HIGHSeaweedFS: Filer JWT allowed_prefixes literal prefix match allows cross-tenant access to sibling pathsEPSS 0.4%