Out-of-bounds write in Linux kernel - CVE-2026-64440

CSH
CYBERSECURITY HELP
Sign In REGISTER
 
Main Vulnerability Database Vulnerabilities #VU139503

Out-of-bounds write in Linux kernel - CVE-2026-64440

Published: July 27, 2026


Vulnerability identifier: #VU139503
CSH Severity: High
CVSS v4: 7.2 [CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-64440
CWE-ID: CWE-787
Exploitation vector: Adjecent network
Exploit availability: No public exploit available

Vulnerability details

The vulnerability allows a remote attacker to cause memory corruption.

The vulnerability exists due to an out-of-bounds write in HT_caps_handler() when parsing a crafted 802.11 association response frame. A remote attacker can send a malicious access point response with an oversized HT Capabilities information element to cause memory corruption.

The issue can write beyond the fixed 26-byte HT_cap array into adjacent fields of struct mlme_ext_info.


Affected software

Linux kernel
Ubuntu
linux (Ubuntu package)
linux-gcp-7.0 (Ubuntu package)
linux-oem-7.0 (Ubuntu package)

How to mitigate CVE-2026-64440

Install security update from vendor's repository.

Linux kernel - update to 7.0 rc3
linux (Ubuntu package) - addressed in versions 7.0.0-31.31, 7.0.0-31.31.1, 7.0.0-31.31~24.04.1, 7.0.0-1006.7, 7.0.0-1011.11~24.04.1, 7.0.0-1012.12, 7.0.0-1012.12~24.04.1
linux-gcp-7.0 (Ubuntu package) - update to 7.0.0-1011.11~24.04.1
linux-oem-7.0 (Ubuntu package) - update to 7.0.0-1013.13

External References

Related Security Bulletins