CVE-2026-43384
Analyzed Analyzed - Analysis Complete
Constant-Time MAC Comparison Fix in Linux Kernel TCP-AO

Publication date: 2026-05-08

Last updated on: 2026-05-26

Assigner: kernel.org

Description
In the Linux kernel, the following vulnerability has been resolved: net/tcp-ao: Fix MAC comparison to be constant-time To prevent timing attacks, MACs need to be compared in constant time. Use the appropriate helper function for this.
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Meta Information
Published
2026-05-08
Last Modified
2026-05-26
Generated
2026-06-19
AI Q&A
2026-05-08
EPSS Evaluated
2026-06-18
NVD
CVE-2026-43384
EUVD
EUVD-2026-28690
Affected Vendors & Products
Showing 5 associated CPEs
Vendor Product Version / Range
linux linux_kernel 7.0
linux linux_kernel 7.0
linux linux_kernel From 6.13 (inc) to 6.18.19 (exc)
linux linux_kernel From 6.7 (inc) to 6.12.78 (exc)
linux linux_kernel From 6.19 (inc) to 6.19.9 (exc)
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Exploitability
CWE
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KEV
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CWE ID Description
CWE-UNKNOWN
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Executive Summary

This vulnerability in the Linux kernel relates to the way Message Authentication Codes (MACs) are compared in the net/tcp-ao component.

The issue was that MAC comparisons were not done in constant time, which could allow timing attacks.

The fix involved using an appropriate helper function to ensure MAC comparisons are performed in constant time, preventing attackers from gaining information based on the time it takes to compare MACs.

Impact Analysis

If exploited, this vulnerability could allow an attacker to perform timing attacks to potentially deduce the MAC values used in TCP authentication.

This could lead to unauthorized access or manipulation of network communications that rely on these MACs for integrity and authentication.

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