CyberSecBulletin
CVE-2026-77317NVD status: Deferred

seaweedfs: Incorrect Authorization

Published Updated By the CyberSecBulletin desk

CVE-2026-77317 is a high-severity incorrect authorization vulnerability in seaweedfs, with a CVSS 3.1 base score of 8.1 out of 10. It can be exploited remotely over the network by an attacker with a low-privileged account, without any action from a user. Affected seaweedfs versions: >= 3.88, < 4.40. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.36% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Check which version of seaweedfs you run against the affected versions below, and install the vendor's latest release.
  2. Read the advisory on github.com for workarounds and exact fixed builds.

Affected products and versions

VendorProductAffected versionsFixed in
Seaweedfsseaweedfs>= 3.88, < 4.40Not stated

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
LowA basic user account is enough.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
HighAll data handled by the component can be read.
Integrity
HighData or code can be modified at will.
Availability
NoneAvailability is not affected.

Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N. Scored by CNA (github.com).

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.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Incorrect Authorization

The product performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the check.

How developers prevent this class of flaw

  • Divide the product into anonymous, normal, privileged, and administrative areas. Reduce the attack surface by carefully mapping roles with data and functionality. Use role-based access control (RBAC) to enforce the roles at the appropriate boundaries. Note that this approach may not protect against horizontal authorization, i.e., it will not protect a user from attacking others with the same role.
  • Ensure that access control checks are performed related to the business logic. These checks may be different than the access control checks that are applied to more generic resources such as files, connections, processes, memory, and database records. For example, a database may restrict access for medical records to a specific database user, but each record might only be intended to be accessible to the patient and the patient's doctor.
  • Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. For example, consider using authorization frameworks such as the JAAS Authorization Framework and the OWASP ESAPI Access Control feature.

More Incorrect Authorization vulnerabilities (CWE-863)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: poc, automatable: no, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Other vulnerabilities in seaweedfs

All seaweedfs vulnerabilities

Recent Incorrect Authorization vulnerabilities

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