CVE-2026-46101 PUBLISHED

netfilter: reject zero shift in nft_bitwise

Assigner: Linux
Reserved: 13.05.2026 Published: 27.05.2026 Updated: 27.05.2026

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.

Product Status

Vendor Linux
Product Linux
Versions Default: unaffected
  • affected from 567d746b55bc66d3800c9ae91d50f0c5deb2fd93 to bffef0acec9c3b837a785248a893137fb7f26c95 (excl.)
  • affected from 567d746b55bc66d3800c9ae91d50f0c5deb2fd93 to ca24f1243ad1a4d12d6a23876bbbe3ed02099853 (excl.)
  • affected from 567d746b55bc66d3800c9ae91d50f0c5deb2fd93 to 6f820139d16a4c9865a145d4a9cf9c92cc632c14 (excl.)
  • affected from 567d746b55bc66d3800c9ae91d50f0c5deb2fd93 to f370205974f171a5868c13ff30d7642fed46e47b (excl.)
  • affected from 567d746b55bc66d3800c9ae91d50f0c5deb2fd93 to fe11e5c40817b84abaa5d83bfb6586d8412bfd07 (excl.)
Vendor Linux
Product Linux
Versions Default: affected
  • Version 5.6 is affected
  • unaffected from 0 to 5.6 (excl.)
  • unaffected from 6.6.140 to 6.6.* (incl.)
  • unaffected from 6.12.86 to 6.12.* (incl.)
  • unaffected from 6.18.27 to 6.18.* (incl.)
  • unaffected from 7.0.4 to 7.0.* (incl.)
  • unaffected from 7.1-rc2 to * (incl.)

References