CVE-2026-46101

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.

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EPSS — Exploit Prediction

0.0018

Probability of exploitation

0.07%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

References

Other References

https://git.kernel.org/stable/c/4fccea585631621c975883911a08d15b6671f7dc https://git.kernel.org/stable/c/6f820139d16a4c9865a145d4a9cf9c92cc632c14 https://git.kernel.org/stable/c/9ad26c272405f53834871cc2e46b9b5393a666c3 https://git.kernel.org/stable/c/9baa08d6b6b096fad70049533f0d705d85fdc979 https://git.kernel.org/stable/c/bffef0acec9c3b837a785248a893137fb7f26c95 https://git.kernel.org/stable/c/ca24f1243ad1a4d12d6a23876bbbe3ed02099853 https://git.kernel.org/stable/c/f370205974f171a5868c13ff30d7642fed46e47b https://git.kernel.org/stable/c/fe11e5c40817b84abaa5d83bfb6586d8412bfd07

Frequently Asked Questions

What is CVE-2026-46101? +

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.

How do I check if I'm vulnerable to CVE-2026-46101? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.