Improper control of a resource through its lifetime in Linux kernel - CVE-2026-89487
Published: September 12, 2026
Vulnerability identifier: #VU149320
CSH Severity: Low
CVSS v4: 5.7 [CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-89487
CWE-ID: CWE-664
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a local user to modify page-cache data.
The vulnerability exists due to improper handling of zero-copy packet buffer flags in the Open vSwitch datapath when a failed USERSPACE upcall is followed by local ESP-in-UDP delivery. A local user can trigger a failed USERSPACE upcall followed by local ESP-in-UDP delivery to modify page-cache data.
Exploitation requires a MSG_ZEROCOPY packet carrying page-cache fragments.
Affected software
Linux kernel
How to mitigate CVE-2026-89487
Install security update from vendor's repository.