Vulnerability in Linux

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.

Published · last modified .

CVSS v3 metric

CVSS v3 base score 9.4 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:H.

EPSS exploit prediction

EPSS: 0.007 (49.2th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 49th percentile — 49.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-43383: held from 0.004 to 0.007.

EPSS over last 30 days · oldest: 0.004 · newest: 0.007 · change: +0.002

Affected products

References

Frequently asked questions

What is CVE-2026-43383?
CVE-2026-43383 is a critical-severity vulnerability in Linux. CVSS score: 9.4/10. Published 2026-05-08.
How severe is CVE-2026-43383?
Critical severity. CVSS v3 base score is 9.4 out of 10.