Use-after-free in Linux kernel - CVE-2026-45837

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Main Vulnerability Database Vulnerabilities #VU132653

Use-after-free in Linux kernel - CVE-2026-45837

Published: May 28, 2026


Vulnerability identifier: #VU132653
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-2026-45837
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.

The vulnerability exists due to use-after-free in arena_vm_close and bpf_arena_free_pages when handling inherited arena VMAs after a fork. A local user can trigger a stale VMA reference by calling bpf_arena_free_pages() in a child process after the parent unmaps the arena to cause a denial of service.

The issue occurs when an arena VMA is inherited across fork and the child retains a pointer to the parent VMA.


Affected software

Linux kernel
Ubuntu
linux (Ubuntu package)
linux-realtime (Ubuntu package)
linux-gcp (Ubuntu package)
linux-oracle (Ubuntu package)
linux-aws (Ubuntu package)
linux-azure (Ubuntu package)
linux-raspi (Ubuntu package)
linux-nvidia (Ubuntu package)
linux-ibm (Ubuntu package)
linux-nvidia-bos (Ubuntu package)
linux-oracle-7.0 (Ubuntu package)
linux-gcp-7.0 (Ubuntu package)
linux-azure-7.0 (Ubuntu package)
linux-oem-7.0 (Ubuntu package)
linux-gke (Ubuntu package)
linux-azure-fde (Ubuntu package)
linux-nvidia-7.0 (Ubuntu package)

How to mitigate CVE-2026-45837

Install security update from vendor's repository.

Linux kernel - update to 7.0 rc3
linux (Ubuntu package) - update to 7.0.0-28.28
linux-realtime (Ubuntu package) - update to 7.0.0-28.28.1
linux-gcp (Ubuntu package) - update to 7.0.0-1008.8
linux-oracle (Ubuntu package) - update to 7.0.0-1008.8
linux-aws (Ubuntu package) - update to 7.0.0-1009.9
linux-azure (Ubuntu package) - update to 7.0.0-1010.10
linux-raspi (Ubuntu package) - update to 7.0.0-1015.15
linux-nvidia (Ubuntu package) - update to 7.0.0-1016.16
linux-ibm (Ubuntu package) - update to 7.0.0-1010.10
linux-nvidia-bos (Ubuntu package) - update to 7.0.0-2016.16
linux-oracle-7.0 (Ubuntu package) - update to 7.0.0-1011.11~24.04.1
linux-gcp-7.0 (Ubuntu package) - update to 7.0.0-1011.11~24.04.1
linux-azure-7.0 (Ubuntu package) - update to 7.0.0-1014.14~24.04.1
linux-oem-7.0 (Ubuntu package) - update to 7.0.0-1009.9
linux-gke (Ubuntu package) - update to 7.0.0-1003.4
linux-azure-fde (Ubuntu package) - update to 7.0.0-1009.9
linux-nvidia-7.0 (Ubuntu package) - update to 7.0.0-1016.16~24.04.1

External References

Related Security Bulletins