CVE-2026-43383

net/tcp-md5: Fix MAC comparison to be constant-time

State: Published
Severity: 9.4 Critical
Published: May 8, 2026
Updated: Oct 19, 2026
Reserved: May 1, 2026

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.

Scores

CVSS	Score	Vector	Source
3.1	9.4 Critical	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:H	Linux

Weaknesses

CWE-208 Observable Timing Discrepancy

Affected Products

Product	Versions
LinuxLinux	cfb6eeb4c860592edd123fdea908d23c6ad1c7dc to before 821c8751fdeecdeecabeb11704dd33439c9e4bbcAffected cfb6eeb4c860592edd123fdea908d23c6ad1c7dc to before ff44ec94d4fc8348600a69de0a8fa1102c23bce8Affected cfb6eeb4c860592edd123fdea908d23c6ad1c7dc to before 345a9530756528d7ca407663d659c3c40e75c3ddAffected cfb6eeb4c860592edd123fdea908d23c6ad1c7dc to before 5d305a95130a8d08b9545e47f1e18d29d59866cbAffected cfb6eeb4c860592edd123fdea908d23c6ad1c7dc to before 02669e2a4d207068edce7e8b5fafd85822018ce6Affected cfb6eeb4c860592edd123fdea908d23c6ad1c7dc to before ae3831b44f477de048287493e184fc3ff913b624Affected cfb6eeb4c860592edd123fdea908d23c6ad1c7dc to before b502e97e29d791ff7a8051f29a414535739be218Affected cfb6eeb4c860592edd123fdea908d23c6ad1c7dc to before 46d0d6f50dab706637f4c18a470aac20a21900d3Affected
LinuxLinux	2.6.20Affected before 2.6.20Not affected 5.10.253 through 5.10.Not affected 5.15.210 through 5.15.Not affected 6.1.167 through 6.1.Not affected 6.6.130 through 6.6.Not affected 6.12.78 through 6.12.Not affected 6.18.19 through 6.18.Not affected 6.19.9 through 6.19.*Not affected 7.0 and laterNot affected

Product

Versions

LinuxLinux

cfb6eeb4c860592edd123fdea908d23c6ad1c7dc to before 821c8751fdeecdeecabeb11704dd33439c9e4bbcAffected
cfb6eeb4c860592edd123fdea908d23c6ad1c7dc to before ff44ec94d4fc8348600a69de0a8fa1102c23bce8Affected
cfb6eeb4c860592edd123fdea908d23c6ad1c7dc to before 345a9530756528d7ca407663d659c3c40e75c3ddAffected
cfb6eeb4c860592edd123fdea908d23c6ad1c7dc to before 5d305a95130a8d08b9545e47f1e18d29d59866cbAffected
cfb6eeb4c860592edd123fdea908d23c6ad1c7dc to before 02669e2a4d207068edce7e8b5fafd85822018ce6Affected
cfb6eeb4c860592edd123fdea908d23c6ad1c7dc to before ae3831b44f477de048287493e184fc3ff913b624Affected
cfb6eeb4c860592edd123fdea908d23c6ad1c7dc to before b502e97e29d791ff7a8051f29a414535739be218Affected
cfb6eeb4c860592edd123fdea908d23c6ad1c7dc to before 46d0d6f50dab706637f4c18a470aac20a21900d3Affected

LinuxLinux

2.6.20Affected
before 2.6.20Not affected
5.10.253 through 5.10.*Not affected
5.15.210 through 5.15.*Not affected
6.1.167 through 6.1.*Not affected
6.6.130 through 6.6.*Not affected
6.12.78 through 6.12.*Not affected
6.18.19 through 6.18.*Not affected
6.19.9 through 6.19.*Not affected
7.0 and laterNot affected

References

Every record here comes from the CVE Program’s CVE List. © 1999–2026 The MITRE Corporation. CVE is a registered trademark of The MITRE Corporation. The records are reproduced under the CVE Program terms of use.