Improper control of a resource through its lifetime in Linux kernel - CVE-2026-90042

Vulnerability identifier: #VU150244

CSH Severity: High

CVSS v4: 9.3 [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]

CVE-ID: CVE-2026-90042

CWE-ID: CWE-664

Exploitation vector: Remote access

Exploit availability: No public exploit available

The vulnerability allows a remote attacker to cause a denial of service.

The vulnerability exists due to improper handling of non-linear memory buffers in ceph_fname_to_usr() when processing MDS messages held in vmalloc()-allocated buffers. A remote attacker can cause a message containing encrypted filenames to be processed to cause a denial of service.

The issue can result in kernel oopses, especially on non-x86 platforms.

Linux kernel
Debian Linux
Ubuntu
linux (Ubuntu package)
linux-aws (Ubuntu package)
linux-gcp (Ubuntu package)
linux-oracle (Ubuntu package)
linux-ibm (Ubuntu package)
linux-hwe-7.0 (Ubuntu package)
linux-oem-7.0 (Ubuntu package)
linux (Debian package)

Install security update from vendor's repository.

linux (Ubuntu package) - update to 7.0.0-42.42
linux-aws (Ubuntu package) - update to 7.0.0-1016.17
linux-gcp (Ubuntu package) - update to 7.0.0-1016.18
linux-oracle (Ubuntu package) - update to 7.0.0-1015.16
linux-ibm (Ubuntu package) - update to 7.0.0-1017.17
linux-hwe-7.0 (Ubuntu package) - update to 7.0.0-42.42~24.04.1
linux-oem-7.0 (Ubuntu package) - update to 7.0.0-1017.17
linux (Debian package) - update to 6.12.111-1

• https://git.kernel.org/stable/c/110747ff535e3d98ac17d68dbd056bb6ef000e23
• https://git.kernel.org/stable/c/3b467c68803d7c7e82678289e598afd44faa6101
• https://git.kernel.org/stable/c/e939fc6a7bd969a58a150b7f188c1047138403e3

• Improper control of a resource through its lifetime in Linux kernel ceph
• Debian update for linux
• Ubuntu update for linux-oem-7.0
• Ubuntu update for linux, linux-aws, linux-gcp and more