Division by zero in Linux kernel - CVE-2026-45889
Published: May 28, 2026
Vulnerability identifier: #VU132607
CSH Severity: Low
CVSS v4: 5.7 [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]
CVE-ID: CVE-2026-45889
CWE-ID: CWE-369
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 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.
Affected software
Linux kernel
How to mitigate CVE-2026-45889
Install security update from vendor's repository.