01 Record

CVE-2026-43383

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

CriticalPUBLISHEDCNA: Linux

CNA base score9.4 CVSS v3.xCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:H

View raw JSON

02 Description

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

03 Exploitation and scoring

Exploitation

Assessed, none found. CISA's assessment recorded neither public exploit code nor evidence of exploitation when it was made.

SSVC decision

ExploitationnoneCISA recorded no public exploit code and no evidence of exploitation.
AutomatableyesAn attacker can reliably automate reconnaissance through exploitation, so this scales.
Technical ImpactpartialSuccessful exploitation gives limited control of the vulnerable component.

CISA publishes the decision points, not a final SSVC decision. The decision also depends on mission and well-being impact, which is a property of your deployment rather than of the vulnerability.

EPSS probability

0.54% probability of exploitation activity in the next 30 days.

EPSS percentile

Equal to or higher than the score of 45.2% of scored records. A rank, not a probability.

NVD base score

9.4 (CVSS v3.x), scored by the NVD independently of the CNA.

NVD CVSS vector

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

NVD analysis status

Modified. NVD last modified this record on 2026-10-19.

Red Hat severity

Moderate. Red Hat's rating for its own products, not a CVSS rating.

Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.

04 Metadata

Published

2026-05-08 14:21Z5 MO AGO

Last updated

2026-10-19 19:16Z9 DAYS AGO

Reserved

2026-05-01

Assigning CNA

Linux

Record state

PUBLISHED

Severity

Critical (CVSS 9.4)

CNA CVSS vector

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

Weaknesses

CWE-208Observable Timing DiscrepancyBase

Data version

5.2

Document digest

deb97948a1b59142511a1ad7ee97004a821d1927c6e4e295f5d80edbb532aef1

05 Affected products

VendorProductVersionsPlatforms

LinuxLinuxcfb6eeb4c860592edd123fdea908d23c6ad1c7dc to < 821c8751fdeecdeecabeb11704dd33439c9e4bbc, cfb6eeb4c860592edd123fdea908d23c6ad1c7dc to < ff44ec94d4fc8348600a69de0a8fa1102c23bce8, cfb6eeb4c860592edd123fdea908d23c6ad1c7dc to < 345a9530756528d7ca407663d659c3c40e75c3dd, cfb6eeb4c860592edd123fdea908d23c6ad1c7dc to < 5d305a95130a8d08b9545e47f1e18d29d59866cb, cfb6eeb4c860592edd123fdea908d23c6ad1c7dc to < 02669e2a4d207068edce7e8b5fafd85822018ce6, cfb6eeb4c860592edd123fdea908d23c6ad1c7dc to < ae3831b44f477de048287493e184fc3ff913b624, cfb6eeb4c860592edd123fdea908d23c6ad1c7dc to < b502e97e29d791ff7a8051f29a414535739be218, cfb6eeb4c860592edd123fdea908d23c6ad1c7dc to < 46d0d6f50dab706637f4c18a470aac20a21900d3, 2.6.20—

06 References

git.kernel.orghttps://git.kernel.org/stable/c/821c8751fdeecdeecabeb11704dd33439c9e4bbc
git.kernel.orghttps://git.kernel.org/stable/c/ff44ec94d4fc8348600a69de0a8fa1102c23bce8
git.kernel.orghttps://git.kernel.org/stable/c/345a9530756528d7ca407663d659c3c40e75c3dd
git.kernel.orghttps://git.kernel.org/stable/c/5d305a95130a8d08b9545e47f1e18d29d59866cb
git.kernel.orghttps://git.kernel.org/stable/c/02669e2a4d207068edce7e8b5fafd85822018ce6
git.kernel.orghttps://git.kernel.org/stable/c/ae3831b44f477de048287493e184fc3ff913b624
git.kernel.orghttps://git.kernel.org/stable/c/b502e97e29d791ff7a8051f29a414535739be218
git.kernel.orghttps://git.kernel.org/stable/c/46d0d6f50dab706637f4c18a470aac20a21900d3

07 Fixed in

Debian 12

linux
Fixed in 6.1.170-1

Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.

Debian 13

linux
Fixed in 6.12.85-1

Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.

Debian 14

linux
Fixed in 6.19.10-1

Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.