Out-of-bounds write in Linux kernel - CVE-2026-89579
Published: September 12, 2026
Vulnerability identifier: #VU149222
CSH Severity: Low
CVSS v4: 8.4 [CVSS:4.0/AV:L/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-89579
CWE-ID: CWE-787
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a local privileged user to escalate privileges.
The vulnerability exists due to out-of-bounds memory access in the BPF bloom filter bitset allocation and indexing logic when processing BPF bloom filter map operations on 32-bit kernels. A local privileged user can create a bloom filter map with a maximal bitset and perform updates to escalate privileges.
Exploitation is possible on 32-bit x86 kernels from a binary with CAP_BPF.
Affected software
Linux kernel
How to mitigate CVE-2026-89579
Install security update from vendor's repository.