Auth bypass in Alluxio
CVE-2026-79787
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.
Vulnerability class: Broken Authentication
CVSS v3 metric
CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.
Affected products
Weakness classification (CWE)
References
- disclosure@vulncheck.com (product)
- disclosure@vulncheck.com (issue-tracking)
- disclosure@vulncheck.com (technical-description)
- disclosure@vulncheck.com (third-party-advisory)
Frequently asked questions
- What is CVE-2026-79787?
- CVE-2026-79787 is a critical-severity vulnerability in Alluxio, classified under Improper Authentication. CVSS score: 9.8/10. Published 2026-08-25.
- How severe is CVE-2026-79787?
- Critical severity. CVSS v3 base score is 9.8 out of 10.