Medium severity · published May 27, 2026
CVE-2026-46101
netfilter: reject zero shift in nft_bitwise
5.5
CVSS
0.1%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Attack vector
Local
Complexity
Low
Privileges
Low
User interaction
None
Confidentiality
None
Integrity
None
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.1% · higher than 2% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
KE
Kernel · Linux
5.6 before 5.10.258; 5.11 before 5.15.209; 5.16 before 6.1.175; 6.2 before 6.6.140; 6.7 before 6.12.86; 6.13 before 6.18.27; +2 more · source: NVD
LI
Linux · Linux
567d746b55bc66d3800c9ae91d50f0c5deb2fd93 before 9baa08d6b6b096fad70049533f0d705d85fdc979; 567d746b55bc66d3800c9ae91d50f0c5deb2fd93 before 4fccea585631621c975883911a08d15b6671f7dc; 567d746b55bc66d3800c9ae91d50f0c5deb2fd93 before 9ad26c272405f53834871cc2e46b9b5393a666c3; 567d746b55bc66d3800c9ae91d50f0c5deb2fd93 before bffef0acec9c3b837a785248a893137fb7f26c95; 567d746b55bc66d3800c9ae91d50f0c5deb2fd93 before ca24f1243ad1a4d12d6a23876bbbe3ed02099853; 567d746b55bc66d3800c9ae91d50f0c5deb2fd93 before 6f820139d16a4c9865a145d4a9cf9c92cc632c14; +3 more · source: vendor
SS
SIMATIC S7-1500 CPU 1518-4 PN/DP MFP · Siemens
V3.1.6; V3.1.7; V3.1.6; V3.1.7 · source: CISA
SS
SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP · Siemens
V3.1.6; V3.1.7; V3.1.6; V3.1.7 · source: CISA
SS
SIMATIC S7-1500 TM MFP - GNU/Linux subsystem · Siemens
0 · source: CISA
SS
SIPLUS S7-1500 CPU 1518-4 PN/DP MFP · Siemens
V3.1.6; V3.1.7 · source: CISA
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-46101
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-46101
Patch
https://git.kernel.org/stable/c/4fccea585631621c975883911a08d15b6671f7dc
Patch
https://git.kernel.org/stable/c/6f820139d16a4c9865a145d4a9cf9c92cc632c14
Patch
https://git.kernel.org/stable/c/9ad26c272405f53834871cc2e46b9b5393a666c3
Patch
https://git.kernel.org/stable/c/9baa08d6b6b096fad70049533f0d705d85fdc979
Patch
https://git.kernel.org/stable/c/bffef0acec9c3b837a785248a893137fb7f26c95
Patch
https://git.kernel.org/stable/c/ca24f1243ad1a4d12d6a23876bbbe3ed02099853
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