CVE-2026-46101

netfilter: reject zero shift in nft_bitwise

MEDIUM
5.5
CVSS Score
Published: May 27, 2026 at 12:59 PM UTC
Updated: October 15, 2026 at 02:19 AM UTC
4 products affected across 2 vendorsLinux KernelSIMATIC S7-1500 CPU 1518-4 Pn /dp MFP FirmwareSiplus S7-1500 CPU 1518-4 Pn /dp MFP Firmware

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Severity
MEDIUM5.5
Exploit prediction
EPSS 0.1%

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

5.11 ≤ v < 5.15.2095.16 ≤ v < 6.1.1755.6 ≤ v < 5.10.2586.13 ≤ v < 6.18.276.19 ≤ v < 7.0.46.2 ≤ v < 6.6.1406.7 ≤ v < 6.12.86567d746b55bc66d3800c9ae91d50f0c5deb2fd937.17.1 rc1
Vendor states this is fixed in 4fccea585631621c975883911a08d15b6671f7dc (fixed)
Vendor states this is fixed in 6f820139d16a4c9865a145d4a9cf9c92cc632c14 (fixed)
Vendor states this is fixed in 9ad26c272405f53834871cc2e46b9b5393a666c3 (fixed)
Vendor states this is fixed in 9baa08d6b6b096fad70049533f0d705d85fdc979 (fixed)
Vendor states this is fixed in bffef0acec9c3b837a785248a893137fb7f26c95 (fixed)
Vendor states this is fixed in ca24f1243ad1a4d12d6a23876bbbe3ed02099853 (fixed)
Vendor states this is fixed in f370205974f171a5868c13ff30d7642fed46e47b (fixed)
Vendor states this is fixed in fe11e5c40817b84abaa5d83bfb6586d8412bfd07 (fixed)
Vendor states this is fixed in 5.10.258 (unaffected)
Vendor states this is fixed in 5.15.209 (unaffected)
Vendor states this is fixed in 5.6 (unaffected)
Vendor states this is fixed in 6.1.175 (unaffected)
Vendor states this is fixed in 6.12.86 (unaffected)
Vendor states this is fixed in 6.18.27 (unaffected)
Vendor states this is fixed in 6.6.140 (unaffected)
Vendor states this is fixed in 7.0.4 (unaffected)
Vendor states this is fixed in 7.1 (unaffected)

CVSS

Attack Vector
LOCAL
Complexity
LOW
Privileges
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusMODIFIED
CWE
NVD-CWE-noinfo

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