CVE-2026-79787

Alluxio through 2.9.5 S3 REST Proxy Authentication Bypass via Unverified Request Signature

Published Aug 25, 2026 CVSS 4.0 · 9.3 Critical EPSS < 1% KEV · Not listed
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'poc', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Type Values Removed Values Added
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.
Title Alluxio through 2.9.5 S3 REST Proxy Authentication Bypass via Unverified Request Signature
First Time appeared Alluxio
Alluxio alluxio
Weaknesses CWE-287
CPEs cpe:2.3:a:alluxio:alluxio:*:*:*:*:*:*:*:*
Vendors & Products Alluxio
Alluxio alluxio
References
Metrics cvssV3_1

{'score': 9.8, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H'}

cvssV4_0

{'score': 9.3, 'vector': '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'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
VulnCheck
Published
Updated
Aug 25, 2026, 6:55 PM
Reserved
Aug 25, 2026, 2:32 PM
Status
Deferred
Published
Aug 25, 2026, 7:16 PM
Modified
Sep 24, 2026, 8:43 PM