Use-after-free in Linux kernel - CVE-2026-98442

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Main Vulnerability Database Vulnerabilities #VU156740

Use-after-free in Linux kernel - CVE-2026-98442

Published: October 22, 2026


Vulnerability identifier: #VU156740
CSH Severity: Medium
CVSS v4: 8.2 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-98442
CWE-ID: CWE-416
Exploitation vector: Remote access
Exploit availability: No public exploit available

Vulnerability details

The vulnerability allows a remote attacker to cause a denial of service or potentially corrupt kernel memory.

The vulnerability exists due to use-after-free in the Linux kernel connection-tracking action in net/sched/act_ct.c when connection-tracking extensions are reallocated after a helper creates an expectation for an unconfirmed connection. A remote attacker can trigger processing of network traffic that exercises this sequence to leave a stale pointer in the expectations list, potentially causing a kernel crash or memory corruption when the expectation is removed.


Affected software

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)

How to mitigate CVE-2026-98442

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

External References

Related Security Bulletins