Use-after-free in Linux kernel - CVE-2026-74436

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Main Vulnerability Database Vulnerabilities #VU142663

Use-after-free in Linux kernel - CVE-2026-74436

Published: August 15, 2026


Vulnerability identifier: #VU142663
CSH Severity: Low
CVSS v4: 6.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-74436
CWE-ID: CWE-416
Exploitation vector: Local access
Exploit availability: No public exploit available

Vulnerability details

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

The vulnerability exists due to a use-after-free in rxrpc_kernel_charge_accept() and the rxrpc service backlog handling when concurrent socket teardown and kernel accept preallocation occur. A local attacker can trigger concurrent operations that reuse a freed backlog structure to cause a denial of service.

The issue arises from a race condition between kernel preallocation work and socket teardown in the RxRPC subsystem.


Affected software

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

How to mitigate CVE-2026-74436

Install security update from vendor's repository.

Linux kernel - update to 7.0 rc3
linux (Ubuntu package) - addressed in versions 7.0.0-34.34, 7.0.0-34.34.1, 7.0.0-34.34~24.04.1, 7.0.0-1012.12~24.04.1, 7.0.0-1013.13, 7.0.0-1013.13~24.04.1, 7.0.0-1014.14, 7.0.0-1020.20
linux-gcp (Ubuntu package) - addressed in versions 7.0.0-1013.13, 7.0.0-1013.13~24.04.1, 7.0.0-1014.14

External References

Related Security Bulletins