CVE-2026-77317 SeaweedFS: SFTP path ACL literal prefix match permits cross-tenant file read and overwrite
Authenticated SFTP users can bypass path ACLs to read or overwrite other tenants' files due to improper prefix matching.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-77317?
CVE-2026-77317 is a high-severity missing authorization vulnerability in seaweedfs, published on 26 Aug 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
SeaweedFS is a distributed storage system for files and blobs. In versions from 3.88 through 4.39, the SFTP server evaluates configured path permissions with a literal string-prefix comparison, so a user scoped to a path is also granted the same access to any sibling path whose name merely begins with the same characters. A user granted access to /tenants/alice therefore also matches /tenants/alice-archive, /tenants/alice2, and similar siblings, because the check does not require a path-component boundary. An authenticated low-privilege SFTP user with a root home directory and narrow path permissions can thereby cross the configured ACL boundary to read another tenant's files, and to overwrite them if granted write, all through the documented SFTP service with its own valid credentials. This issue is fixed in version 4.40.
Weakness: CWE-863
Which versions are affected by CVE-2026-77317?
1 open source package ship an affected version, including seaweedfs.
| Package | Affected | Fixed in |
|---|---|---|
seaweedfs Bitnami | From 3.88.0 | 4.40.0 |
How do I fix CVE-2026-77317?
Upgrade seaweedfs to 4.40.0 or later.
Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.
Is CVE-2026-77317 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-77317 exists.
Sources
Also known as BIT-seaweedfs-2026-77317, GHSA-fvpg-g364-j8vh, MINI-96gh-x663-8cmw.