CyberSecBulletin
CVE-2026-43030NVD status: Modified

Linux: Incorrect Calculation

Published Updated By the CyberSecBulletin desk

CVE-2026-43030 is a high-severity incorrect calculation vulnerability in Linux, with a CVSS 3.1 base score of 7.8 out of 10. It can be exploited with local access to the system by an attacker with a low-privileged account, without any action from a user. The record lists versions b52f6d0ef7b308f9d05bbddb78749852f28e8e40, 37db6b9726d0bcf91cbdf9d63b558c50da49f968, 015a74476dc1ab6923d89f1ee009aaf43faa7185 as the first without the flaw, so updating Linux to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.14% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update Linux to b52f6d0ef7b308f9d05bbddb78749852f28e8e40 or 37db6b9726d0bcf91cbdf9d63b558c50da49f968 or 015a74476dc1ab6923d89f1ee009aaf43faa7185 or b99d82706bd1511bb875e3de7154698fd9215c99, whichever matches your release line, or a later version.
  2. Update Linux Kernel to 5.10.253 or 5.15.203 or 6.1.168 or 6.6.134, whichever matches your release line, or a later version.

Affected products and versions

VendorProductAffected versionsFixed in
LinuxLinux95b6ec733752b31bfd166c4609d2c1b5cdde9b47 up to, but not including, b52f6d0ef7b308f9d05bbddb78749852f28e8e40; 6d94e741a8ff818e5518da8257f5ca0aaed1f269 up to, but not including, 37db6b9726d0bcf91cbdf9d63b558c50da49f968; 6d94e741a8ff818e5518da8257f5ca0aaed1f269 up to, but not including, 015a74476dc1ab6923d89f1ee009aaf43faa7185; 6d94e741a8ff818e5518da8257f5ca0aaed1f269 up to, but not including, b99d82706bd1511bb875e3de7154698fd9215c99; 6d94e741a8ff818e5518da8257f5ca0aaed1f269 up to, but not including, 7241da033fdc507b920e092dab1f97b945cb0370; 6d94e741a8ff818e5518da8257f5ca0aaed1f269 up to, but not including, 8aebe18069394f4a79d2d82080a0f806da449996; 6d94e741a8ff818e5518da8257f5ca0aaed1f269 up to, but not including, ca995b1462ec6db1e869100ba1fb7356bd3f22f0; 6d94e741a8ff818e5518da8257f5ca0aaed1f269 up to, but not including, a8502a79e832b861e99218cbd2d8f4312d62e225; and 2 more rangesb52f6d0ef7b308f9d05bbddb78749852f28e8e40, 37db6b9726d0bcf91cbdf9d63b558c50da49f968, 015a74476dc1ab6923d89f1ee009aaf43faa7185, b99d82706bd1511bb875e3de7154698fd9215c99, 7241da033fdc507b920e092dab1f97b945cb0370, 8aebe18069394f4a79d2d82080a0f806da449996
SiemensSIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AB0)V3.1.6 and later; V3.1.5 and later; V3.1.7 and laterNot stated
SiemensSIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AC0)V3.1.6 and later; V3.1.5 and later; V3.1.7 and laterNot stated
SiemensSIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AB0)V3.1.6 and later; V3.1.5 and later; V3.1.7 and laterNot stated
SiemensSIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AC0)V3.1.6 and later; V3.1.5 and later; V3.1.7 and laterNot stated
SiemensSIPLUS S7-1500 CPU 1518-4 PN/DP MFP (6AG1518-4AX00-4AC0)V3.1.6 and later; V3.1.5 and later; V3.1.7 and laterNot stated
LinuxLinux Kernel5.10.155 up to, but not including, 5.10.253; 5.11 up to, but not including, 5.15.203; 5.16 up to, but not including, 6.1.168; 6.2 up to, but not including, 6.6.134; 6.7 up to, but not including, 6.12.81; 6.13 up to, but not including, 6.18.22; 6.19 up to, but not including, 6.19.12; 7.05.10.253, 5.15.203, 6.1.168, 6.6.134, 6.12.81, 6.18.22

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
LocalThe attacker needs local access or must trick a user into running something.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
LowA basic user account is enough.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
HighAll data handled by the component can be read.
Integrity
HighData or code can be modified at will.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. Scored by CNA.

Official description

In the Linux kernel, the following vulnerability has been resolved: bpf: Fix regsafe() for pointers to packet In case rold->reg->range == BEYOND_PKT_END && rcur->reg->range == N regsafe() may return true which may lead to current state with valid packet range not being explored. Fix the bug.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Incorrect Calculation

The product performs a calculation that generates incorrect or unintended results that are later used in security-critical decisions or resource management.

How developers prevent this class of flaw

  • Understand your programming language's underlying representation and how it interacts with numeric calculation. Pay close attention to byte size discrepancies, precision, signed/unsigned distinctions, truncation, conversion and casting between types, not-a-number calculations, and how your language handles numbers that are too large or too small for its underlying representation.
  • Perform input validation on any numeric input by ensuring that it is within the expected range. Enforce that the input meets both the minimum and maximum requirements for the expected range.
  • Use the appropriate type for the desired action. For example, in C/C++, only use unsigned types for values that could never be negative, such as height, width, or other numbers related to quantity.

More Incorrect Calculation vulnerabilities (CWE-682)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Recent Incorrect Calculation vulnerabilities

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