SB2026050789 - Double free in Linux kernel 9p
Published: May 7, 2026
Security Bulletin ID
SB2026050789
CSH Severity
Low
Patch available
YES
Number of vulnerabilities
1
Exploitation vector
Local access
Highest impact
Denial of service
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 1 vulnerability.
1) Double free (CVE-ID: CVE-2026-43249)
CWE-ID: CWE-415 - Double Free
CVSSv4: 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
The vulnerability allows a local user to cause a denial of service.
The vulnerability exists due to double free in xen_9pfs_front_free when handling concurrent back-end change notifications. A local user can trigger concurrent back-end change notifications to cause a denial of service.
The issue can be triggered by a race involving the xenwatch thread and other back-end change notifications.
Remediation
Install update from vendor's website.