Use of a broken or risky cryptographic algorithm in Ceph - CVE-2025-30156
Published: August 21, 2026
Vulnerability identifier: #VU144582
CSH Severity: Medium
CVSS v4: 8.6 [CVSS:4.0/AV:A/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:L/SC:N/SI:N/SA:N]
CVE-ID: CVE-2025-30156
CWE-ID: CWE-327
Exploitation vector: Adjecent network
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote user to bypass authentication and gain cluster-wide access.
The vulnerability exists due to use of a broken or risky cryptographic algorithm in the CephX authentication implementation when processing CephX tickets over the network. A remote user can manipulate observed ciphertext and forge credentials to bypass authentication and gain cluster-wide access.
Exploitation requires a low-privilege CephX key and the ability to observe CephX ciphertext on the local network.
Affected software
Ceph
Fedora
ceph
Fedora
ceph
How to mitigate CVE-2025-30156
Install security update from vendor's website.
Ceph - addressed in versions 19.2.6, 20.2.4
ceph - addressed in versions 19.2.6-1.fc43, 20.2.4-1.fc44
ceph - addressed in versions 19.2.6-1.fc43, 20.2.4-1.fc44