CVE-2026-45971 bpf: Limit bpf program signature size

What is CVE-2026-45971?

CVE-2026-45971 is a medium-severity denial of service vulnerability in Linux kernel, published on 27 May 2026. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

In the Linux kernel, the following vulnerability has been resolved:

bpf: Limit bpf program signature size

Practical BPF signatures are significantly smaller than KMALLOC_MAX_CACHE_SIZE

Allowing larger sizes opens the door for abuse by passing excessive size values and forcing the kernel into expensive allocation paths (via kmalloc_large or vmalloc).

Which versions are affected by CVE-2026-45971?

It affects 1 product.

Products include Linux kernel.

How do I fix CVE-2026-45971?

Apply the vendor's patch.

Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.

Is CVE-2026-45971 being exploited?

There is no known exploitation of CVE-2026-45971 in the wild and no public exploit code.

Other vulnerabilities in Linux kernel

• CVE-2026-53266 Linux Kernel Out-of-Bounds Write Exploited High 8.8
• CVE-2013-6282 Linux Kernel Improper Input Validation Exploited High 8.8
• CVE-2022-0185 Linux Kernel Heap-Based Buffer Overflow Exploited High 8.4
• CVE-2013-2094 Linux Kernel Privilege Escalation Exploited High 8.4
• CVE-2026-53362 Linux Kernel Unspecified Exploited High 7.8

All Linux kernel vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as BELL-CVE-2026-45971, DEBIAN-CVE-2026-45971, GHSA-2prw-x82w-7whc, UBUNTU-CVE-2026-45971.