CyberSecBulletin
CVE-2026-43028NVD status: Modified

Linux: Improper Null Termination

Published Updated By the CyberSecBulletin desk

CVE-2026-43028 is a high-severity improper null termination vulnerability in Linux, with a CVSS 3.1 base score of 7.1 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 bcac50ea0a29d430eedc5ac87b215393b567baa9, ea01c1b219f5a11c66918abaa6f052e5a74041d6, aa6cd4a8863391e0a64f62d8922cb0af732a2cf2 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 0.13% 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 bcac50ea0a29d430eedc5ac87b215393b567baa9 or ea01c1b219f5a11c66918abaa6f052e5a74041d6 or aa6cd4a8863391e0a64f62d8922cb0af732a2cf2 or c2d4a3abb15ca14716c6d8b9ffcbcd7c63626af4, 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
LinuxLinuxc38c4597e4bf3e99860eac98211748e1ecb0e139 up to, but not including, bcac50ea0a29d430eedc5ac87b215393b567baa9; c38c4597e4bf3e99860eac98211748e1ecb0e139 up to, but not including, ea01c1b219f5a11c66918abaa6f052e5a74041d6; c38c4597e4bf3e99860eac98211748e1ecb0e139 up to, but not including, aa6cd4a8863391e0a64f62d8922cb0af732a2cf2; c38c4597e4bf3e99860eac98211748e1ecb0e139 up to, but not including, c2d4a3abb15ca14716c6d8b9ffcbcd7c63626af4; c38c4597e4bf3e99860eac98211748e1ecb0e139 up to, but not including, 673bbd36cba21d10a10f0932f479df7468e26fbb; c38c4597e4bf3e99860eac98211748e1ecb0e139 up to, but not including, f419bdc205894750f4d3ec042bc87a1b9cde1351; c38c4597e4bf3e99860eac98211748e1ecb0e139 up to, but not including, 73124608172890306b85f2206d8b3cac20e324f1; c38c4597e4bf3e99860eac98211748e1ecb0e139 up to, but not including, a958a4f90ddd7de0800b33ca9d7b886b7d40f74e; and 1 more rangesbcac50ea0a29d430eedc5ac87b215393b567baa9, ea01c1b219f5a11c66918abaa6f052e5a74041d6, aa6cd4a8863391e0a64f62d8922cb0af732a2cf2, c2d4a3abb15ca14716c6d8b9ffcbcd7c63626af4, 673bbd36cba21d10a10f0932f479df7468e26fbb, f419bdc205894750f4d3ec042bc87a1b9cde1351
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 Kernel4.5 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
NoneNothing can be modified.
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:N/A:H. Scored by CNA.

Official description

In the Linux kernel, the following vulnerability has been resolved: netfilter: x_tables: ensure names are nul-terminated Reject names that lack a \0 character before feeding them to functions that expect c-strings. Fixes tag is the most recent commit that needs this change.

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

The underlying weakness: Improper Null Termination

The product does not terminate or incorrectly terminates a string or array with a null character or equivalent terminator.

How developers prevent this class of flaw

  • Use a language that is not susceptible to these issues. However, be careful of null byte interaction errors (CWE-626) with lower-level constructs that may be written in a language that is susceptible.
  • Ensure that all string functions used are understood fully as to how they append null characters. Also, be wary of off-by-one errors when appending nulls to the end of strings.
  • If performance constraints permit, special code can be added that validates null-termination of string buffers, this is a rather naive and error-prone solution.

More Improper Null Termination vulnerabilities (CWE-170)

Timeline

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

References

Recent Improper Null Termination vulnerabilities

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