Out-of-bounds write in Linux kernel - CVE-2026-90069

Vulnerability identifier: #VU151420

CSH Severity: Low

CVSS v4: 2 [CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-90069

CWE-ID: CWE-787

Exploitation vector: Local access

Exploit availability: No public exploit available

The vulnerability allows a local user to perform an out-of-bounds write.

The vulnerability exists due to insufficient allocation of cloned asynchronous compression request contexts in acomp_request_clone() when cloning a stack-based asynchronous compression request. A local user can trigger use of an asynchronous implementation that writes through acomp_request_ctx() beyond the cloned request allocation to perform an out-of-bounds write.

Only configurations that select an asynchronous compression implementation are affected.

Linux kernel
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)

Install security update from vendor's repository.

Linux kernel - update to 7.0 rc3
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

• https://git.kernel.org/stable/c/889fa17a0af09ff93a9166abc82ee7a654faa49b
• https://git.kernel.org/stable/c/d48197cbd5d3476c7deea644972e9ec510865ec2
• https://git.kernel.org/stable/c/ee440d4fc0d2f15894ab1f64c474a3adbc858880

• Out-of-bounds write in Linux kernel crypto
• Ubuntu update for linux-oem-7.0
• Ubuntu update for linux, linux-aws, linux-gcp and more