SeaweedFS is a distributed storage system for files and blobs. In versions 4.39 and earlier, the S3 API accepts an external OIDC JWT sent directly in the Authorization header and maps it to an IAM role without enforcing that role's trust policy, so a federated user can assume a role they are not permitted to hold. The standard STS AssumeRoleWithWebIdentity path rejects such a token when the role's trust policy does not trust the token's federated provider, but the direct S3 bearer path validates only the token itself and then authenticates as the mapped role and evaluates that role's attached S3 permissions. As a result, a valid OIDC user whose token would be denied the role through STS can obtain the role's S3 access, including object read, write, and delete, by presenting the raw OIDC JWT directly to the S3 API. This issue is fixed in version 4.40
Advisories
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Fixes
Solution
No solution given by the vendor.
Workaround
No workaround given by the vendor.
References
History
Thu, 27 Aug 2026 00:00:00 +0000
| Type | Values Removed | Values Added |
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| First Time appeared |
Seaweedfs
Seaweedfs seaweedfs |
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| Vendors & Products |
Seaweedfs
Seaweedfs seaweedfs |
Wed, 26 Aug 2026 22:00:00 +0000
| Type | Values Removed | Values Added |
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| Description | SeaweedFS is a distributed storage system for files and blobs. In versions 4.39 and earlier, the S3 API accepts an external OIDC JWT sent directly in the Authorization header and maps it to an IAM role without enforcing that role's trust policy, so a federated user can assume a role they are not permitted to hold. The standard STS AssumeRoleWithWebIdentity path rejects such a token when the role's trust policy does not trust the token's federated provider, but the direct S3 bearer path validates only the token itself and then authenticates as the mapped role and evaluates that role's attached S3 permissions. As a result, a valid OIDC user whose token would be denied the role through STS can obtain the role's S3 access, including object read, write, and delete, by presenting the raw OIDC JWT directly to the S3 API. This issue is fixed in version 4.40 | |
| Title | SeaweedFS S3 OIDC Bearer authentication bypasses IAM role trust policy | |
| Weaknesses | CWE-863 | |
| References |
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| Metrics |
cvssV4_0
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Projects
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Status: PUBLISHED
Assigner: GitHub_M
Published:
Updated: 2026-08-26T21:16:51.165Z
Reserved: 2026-08-20T19:17:14.375Z
Link: CVE-2026-77298
No data.
Status : Received
Published: 2026-08-26T22:16:29.570
Modified: 2026-08-26T22:16:29.570
Link: CVE-2026-77298
No data.
OpenCVE Enrichment
Updated: 2026-08-26T23:45:03Z
Weaknesses