SB20260528195 - Division by zero in Linux kernel mptcp
Published: May 28, 2026
Security Bulletin ID
SB20260528195
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) Division by zero (CVE-ID: CVE-2026-45889)
CWE-ID: CWE-369 - Divide By Zero
CVSSv4: CVSS:4.0/AV:L/AC:L/AT:P/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 improper handling of out-of-order data accounting in mptcp_rcvbuf_grow() when processing MPTCP traffic across multiple active subflows. A local user can trigger out-of-order data delivery to cause a kernel divide-by-zero Oops and crash the system.
The issue involves a subtle race condition during rcvspace initialization.
Remediation
Install update from vendor's website.