Authorization Bypass Vulnerability in SeaweedFS Distributed Storage System
CVE-2026-77298

8.7HIGH

Key Information:

Vendor

Seaweedfs

Status
Seaweedfs
Vendor
CVE Published:
26 August 2026

What is CVE-2026-77298?

In versions up to 4.39 of SeaweedFS, an authorization bypass vulnerability exists within the S3 API. The system improperly processes external OIDC JWT tokens sent in the Authorization header, allowing a federated user to bypass role trust policies. This flaw enables users to gain unauthorized access to S3 permissions—including object read, write, and delete operations—by presenting a valid OIDC token directly to the API, instead of utilizing the standard STS AssumeRoleWithWebIdentity path. This vulnerability has been addressed in version 4.40.

Affected Version(s)

seaweedfs < 4.40

References

https://github.com/seaweedfs/seaweedfs/security/advisorie...
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https://github.com/seaweedfs/seaweedfs/commit/ac524e140a3...
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CVSS V4

Score:
8.7
Severity:
HIGH
Confidentiality:
High
Integrity:
High
Availability:
High
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
None

Timeline

  • Vulnerability published

  • Vulnerability Reserved

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