CVE-2026-43383

Description

In the Linux kernel, the following vulnerability has been resolved: net/tcp-md5: 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.

CVSS v3.1 Score

9.4

CRITICAL

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:H

EPSS — Exploit Prediction

0.0011

Probability of exploitation

0.28%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

References

Other References

https://git.kernel.org/stable/c/02669e2a4d207068edce7e8b5fafd85822018ce6 https://git.kernel.org/stable/c/345a9530756528d7ca407663d659c3c40e75c3dd https://git.kernel.org/stable/c/46d0d6f50dab706637f4c18a470aac20a21900d3 https://git.kernel.org/stable/c/5d305a95130a8d08b9545e47f1e18d29d59866cb https://git.kernel.org/stable/c/821c8751fdeecdeecabeb11704dd33439c9e4bbc https://git.kernel.org/stable/c/ae3831b44f477de048287493e184fc3ff913b624 https://git.kernel.org/stable/c/b502e97e29d791ff7a8051f29a414535739be218

Frequently Asked Questions

What is CVE-2026-43383? +

In the Linux kernel, the following vulnerability has been resolved: net/tcp-md5: 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. It has a CVSS v3.1 base score of 9.4 (CRITICAL).

How severe is CVE-2026-43383? +

CVE-2026-43383 has a CVSS v3.1 score of 9.4 out of 10, rated CRITICAL. This is a critical vulnerability that should be patched immediately. The EPSS score is 0.0011, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-43383? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.