---
id: CVE-2026-77298
title: SeaweedFS is a distributed storage system for files and blobs
summary: >-
  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…
severity: none
cwe:
  - CWE-863
published: '2026-08-26'
updated: '2026-09-09'
sourceUpdated: '2026-09-09T21:09:13.080'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-77298'
references:
  - url: >-
      https://github.com/seaweedfs/seaweedfs/commit/ac524e140a37242b2488be9dfffae918da1d4de1
    label: security-advisories@github.com
  - url: >-
      https://github.com/seaweedfs/seaweedfs/security/advisories/GHSA-757h-cm9x-wprg
    label: security-advisories@github.com
tags:
  - nvd
epss: 0.00396
epssPercentile: 0.31094
ingestedAt: '2026-09-09T21:22:45.556Z'
---

## Overview

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

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.