Improper access control in Linux kernel - CVE-2026-74270

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Main Vulnerability Database Vulnerabilities #VU142920

Improper access control in Linux kernel - CVE-2026-74270

Published: August 15, 2026


Vulnerability identifier: #VU142920
CSH Severity: Low
CVSS v4: 6.9 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-74270
CWE-ID: CWE-284
Exploitation vector: Local access
Exploit availability: No public exploit available

Vulnerability details

The vulnerability allows a local user to spoof handshake completion or disrupt an in-flight handshake.

The vulnerability exists due to improper access control in handshake_nl_done_doit() and the handshake genl DONE command when submitting a DONE request for a supplied sockfd without sender authentication. A local user can send a forged DONE message with a chosen status value to spoof handshake success or tear down a legitimate handshake.

The issue affects the DONE downcall of the handshake generic netlink family, where fd lookup confirms only that a pending handshake request exists for the supplied sockfd.


Affected software

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

How to mitigate CVE-2026-74270

Install security update from vendor's repository.

Linux kernel - update to 7.0 rc3
linux-gcp-7.0 (Ubuntu package) - addressed in versions 7.0.0-38.38~24.04.4, 7.0.0-1013.13~24.04.1, 7.0.0-1014.14~24.04.1
linux-azure-7.0 (Ubuntu package) - addressed in versions 7.0.0-1016.16~24.04.1, 7.0.0-1017.17~24.04.1

External References

Related Security Bulletins