CVE-2026-46101 netfilter: reject zero shift in nft_bitwise

What is CVE-2026-46101?

CVE-2026-46101 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:

netfilter: reject zero shift in nft_bitwise

Reject zero shift operands for nft_bitwise left and right shift expressions during initialization.

The carry propagation logic computes the carry from the adjacent 32-bit word using BITS_PER_TYPE(u32) - shift. A zero shift operand turns this into a 32-bit shift, which is undefined behaviour.

Reject zero shift operands in the control plane, alongside the existing check for values greater than or equal to 32, so malformed rules never reach the packet path.

Which versions are affected by CVE-2026-46101?

It affects 1 product.

Products include Linux kernel.

How do I fix CVE-2026-46101?

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-2026-46101 being exploited?

There is no known exploitation of CVE-2026-46101 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 AZL-88502, BELL-CVE-2026-46101, DEBIAN-CVE-2026-46101, GHSA-8x7w-42q6-mv4p, ROOT-OS-DEBIAN-11-CVE-2026-46101, ROOT-OS-DEBIAN-12-CVE-2026-46101 and 3 more.