CVE-2026-93144
kernel: bpf: Reject writes through untrusted BTF pointers
Severity
LowRed Hat Product Security
CVSS 3.1
Review impact separately from score.
Published · September 17, 2026
Updated · October 29, 2026
Description
A flaw was found in the Linux kernel's Berkeley Packet Filter (BPF) subsystem. The check_ptr_to_btf_access() function, which is responsible for validating memory access through BPF Type Format (BTF) pointers, incorrectly allowed certain program-type callbacks to bypass the intended read-only policy for untrusted BTF pointers. This oversight could enable a local attacker to perform unauthorized write operations, potentially leading to privilege escalation within the system.
Statement
The default Red Hat Enterprise Linux kernel prevents unprivileged users from being able to use eBPF by the kernel.unprivileged_bpf_disabled sysctl. This would require a privileged user with CAP_SYS_ADMIN or root to be able to abuse this flaw reducing its attack space.
For the Red Hat Enterprise Linux to confirm the current state, inspect the sysctl with the command:
cat /proc/sys/kernel/unprivileged_bpf_disabled
The setting of 1 would mean that unprivileged users can not use eBPF, mitigating the flaw.
CVSS score applicability
The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.
Mitigation
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.
CVSS / CWE
CVSS 3.1 · 6.7CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
CWE-1220 · Insufficient Granularity of Access Control