CVE-2026-79787
Alluxio through 2.9.5 S3 REST Proxy Authentication Bypass via Unverified Request Signature
- State
- Published
- Severity
- 9.3 Critical
- Published
- Aug 25, 2026
- Updated
- Aug 25, 2026
- Reserved
- Aug 25, 2026
Description
Alluxio's S3 REST proxy fails to verify AWS Signature Version 4 signatures in its default configuration, allowing unauthenticated attackers to spoof user identity. Attackers can extract usernames from unsigned Authorization headers and impersonate any user, including service accounts, to read, write, and delete arbitrary data.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 4.0 | 9.3 Critical | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N | VulnCheck |
| 3.1 | 9.8 Critical | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H | VulnCheck |
Weaknesses
- CWE-287 Improper Authentication
Affected Products
| Product | Versions |
|---|---|
alluxioAlluxio |
|
References
- https://github.com/Alluxio/alluxioproduct
- https://github.com/Alluxio/alluxio/issues/18755issue-tracking
- https://github.com/Alluxio/alluxio/blob/v2.9.5/core/server/proxy/src/main/java/alluxio/proxy/s3/S3RestUtils.javatechnical-description
- VulnCheck Advisory: Alluxio through 2.9.5 S3 REST Proxy Authentication Bypass via Unverified Request Signaturethird-party-advisory
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