SB2026091226 - Out-of-bounds write in Linux kernel mm
Published: September 12, 2026
Security Bulletin ID
SB2026091226
CSH Severity
Low
Patch available
YES
Number of vulnerabilities
1
Exploitation vector
Local access
Highest impact
Data manipulation
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 1 vulnerability.
1) Out-of-bounds write (CVE-ID: CVE-2026-89754)
CWE-ID: CWE-787 - Out-of-bounds write
CVSSv4: 6.9 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows a local user to cause an out-of-bounds write.
The vulnerability exists due to improper state management in the Linux kernel mm/pagewalk page-table walker when walking page tables after a PMD entry is cleared during a retry. A local user can trigger duplicate page-walk callbacks through the mincore system call to cause an out-of-bounds write.
Remediation
Install update from vendor's website.