SB2026032592 - Out-of-bounds write in Linux kernel bpf
Published: March 25, 2026
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 1 security vulnerability.
1) Out-of-bounds write (CVE-ID: CVE-2026-23359)
The vulnerability allows a local user to execute arbitrary code or cause a denial of service.
The vulnerability exists due to a boundary error in the BPF devmap component when handling upper device interface indices. A local user can trigger a stack-out-of-bounds write by creating more than MAX_NEST_DEV (8) macvlans on a device with an XDP program attached using BPF_F_BROADCAST | BPF_F_EXCLUDE_INGRESS and sending a packet to the device, leading to memory corruption.
To exploit this vulnerability, the attacker must have the ability to create macvlan devices and attach XDP programs, which requires local access and privileges to perform network configuration.
Remediation
Install update from vendor's website.
References
- https://git.kernel.org/stable/c/5000e40acc8d0c36ab709662e32120986ac22e7e
- https://git.kernel.org/stable/c/75d474702b2ba8b6bcb26eb3004dbc5e95ffd5d2
- https://git.kernel.org/stable/c/8a95fb9df1105b1618872c2846a6c01e3ba20b45
- https://git.kernel.org/stable/c/b7bf516c3ecd9a2aae2dc2635178ab87b734fef1
- https://git.kernel.org/stable/c/ca831567908fd3f73cf97d8a6c09a5054697a182
- https://git.kernel.org/stable/c/d2c31d8e03d05edc16656e5ffe187f0d1da763d7