PT-2026-39045 · Linux · Linux Kernel

Published 2026-05-08 · Updated 2026-05-26 · CVE-2026-43384

Positive Technologies (AI Summary)

CVSS v3.1

9.8

Critical

Base vector

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

Name of the Vulnerable Software and Affected Versions Linux kernel (affected versions not specified)

Description A timing attack issue exists in the TCP Authentication Option (TCP-AO) implementation. The Message Authentication Code (MAC) comparison was not performed in constant-time, which could allow an attacker to deduce information based on the time taken to validate the MAC.

Recommendations At the moment, there is no information about a newer version that contains a fix for this vulnerability.

Related Identifiers

CVE-2026-43384

Affected Products

Linux Kernel

References · 16

• https://git.kernel.org/stable/c/8be6ed64966da48b6c4726918f106c18742a5125 · Patch
• https://osv.dev/vulnerability/DEBIAN-CVE-2026-43384 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2026-43384 · Security Note
• https://git.kernel.org/stable/c/67edfec516d30d3e62925c397be4a1e5185802fc · Patch
• https://osv.dev/vulnerability/UBUNTU-CVE-2026-43384 · Vendor Advisory
• https://security-tracker.debian.org/tracker/CVE-2026-43384 · Vendor Advisory
• https://git.kernel.org/stable/c/a269cbdc442f8658bca35383e34b9d0b0ff95a1c · Patch
• https://osv.dev/vulnerability/BELL-CVE-2026-43384 · Vendor Advisory
• https://git.kernel.org/stable/c/080b0e210088296dd50d6637c06c1db14246adfe · Patch
• https://ubuntu.com/security/CVE-2026-43384 · Vendor Advisory
• https://cve.org/CVERecord?id=CVE-2026-43384 · Security Note
• https://twitter.com/CVEnew/status/2052810986692677904 · Twitter Post
• https://t.me/cveNotify/164720 · Telegram Post
• https://docs.bell-sw.com/security/cves/CVE-2026-43384 · Note
• https://twitter.com/hetmehtaa/status/2055151398283837677 · Twitter Post