Improper Verification of Cryptographic Signature in Ceph - CVE-2026-54330
Published: August 19, 2026
Vulnerability identifier: #VU144397
CSH Severity: Medium
CVSS v4: 7.6 [CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-54330
CWE-ID: CWE-347
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote user to escalate privileges.
The vulnerability exists due to improper verification of cryptographic signatures in Ceph RGW\'s SigV4 handler when processing presigned PUT requests. A remote user can attach arbitrary unsigned x-amz-* headers to escalate privileges.
Exploitation requires a presigned PUT URL.
Affected software
Ceph
How to mitigate CVE-2026-54330
Install security update from vendor's website.
Ceph - addressed in versions 19.2.6, 20.2.4