Use-after-free in Linux kernel - CVE-2026-98507

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Main Vulnerability Database Vulnerabilities #VU156808

Use-after-free in Linux kernel - CVE-2026-98507

Published: October 22, 2026


Vulnerability identifier: #VU156808
CSH Severity: Low
CVSS v4: 2 [CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-98507
CWE-ID: CWE-416
Exploitation vector: Local access
Exploit availability: No public exploit available

Vulnerability details

The vulnerability allows a local user to cause a denial of service by leaving tasks indefinitely blocked on anonymous memory locks.

The vulnerability exists due to use-after-free caused by a missing memory barrier in __anon_vma_prepare() in mm/rmap.c when publishing an anon_vma during concurrent page faults. A local user can trigger concurrent faults on compatible adjacent memory mappings to cause a stale anon_vma->root pointer to be used, resulting in locking and unlocking different locks and leaving tasks blocked.

The adjacent virtual memory areas must be unmerged but anon_vma-compatible, for example because they differ in access flags that can be changed with mprotect().


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-2026-98507

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