Linux Kernel XFRM Subsystem Use-After-Free Local Privilege Escalation Vulnerability

October 29th, 2026
ZDI-26-837 ZDI-CAN-31604

CVE ID

CVE-2026-98231

CVSS Score

7.8 AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H

Affected Vendors

Linux

Affected Products

Kernel

Vulnerability Details

This vulnerability allows local attackers to escalate privileges on affected installations of Linux Kernel. An attacker must first obtain the ability to execute low-privileged code on the target system in order to exploit this vulnerability.

The specific flaw exists within the xfrm_dev_state_delete function. The issue results from the lack of validating the existence of an object prior to performing operations on the object. An attacker can leverage this vulnerability to escalate privileges and execute arbitrary code in the context of the kernel.

Additional Details

Linux has issued an update to correct this vulnerability. More details can be found at:
https://github.com/torvalds/linux/commit/89fefad9f971bc637fb22373078144f2563c4be9

Disclosure Timeline

  • 2026-07-03 - Vulnerability reported to vendor
  • 2026-10-29 - Coordinated public release of advisory
  • 2026-10-29 - Advisory Updated

Credit

Anonymous

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