Improper Check for Unusual or Exceptional Conditions in Linux kernel - CVE-2026-63955
Published: July 20, 2026
Vulnerability identifier: #VU138692
CSH Severity: Low
CVSS v4.0: 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/E:U/U:Clear
CVE-ID: CVE-2026-63955
CWE-ID: CWE-754
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vendor: Linux Foundation
Affected software:
Linux kernel
Linux kernel
Detailed vulnerability description
The vulnerability allows a local user to cause a denial of service.
The vulnerability exists due to improper handling of interrupt context checks in __get_vm_area_node() when allocating memory through vmalloc() with bottom halves disabled. A local user can trigger a code path that reaches vmalloc() in that context to cause a denial of service.
The issue is triggered by a BUG() condition when bottom halves are disabled, even though execution is not in NMI or hard IRQ context.
How to mitigate CVE-2026-63955
Install security update from vendor's repository.