TI-2026-31562 Aliases CVE-2026-43383 GHSA-m4fq-qc69-83h9

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

MEDIUM 47CWE-208Published 2026-05-08 · Updated 2026-10-19

Key facts

Attack vector: Network
Privileges required: None
User interaction: None
Attack complexity: Low
Impact type: Information disclosure
Confidentiality · integrity · availability: Low · High · High
Fix status: Partial Red Hat: 5 without a fix

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat. Impact type from CWE-208.

Summary

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.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV

EPSS 0.00541 45th percentileScored 2026-11-07

Fix Partial Linux (Linux): 5.10.253, 5.15.210, 6.1.167 +5Red Hat: 5 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation: None
Automatable: Yes
Technical impact: Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

Vendor	Product	Affected versions	Fixed in	Status	Source
Linux	Linux	2.6.20 and later	5.10.253, 5.15.210, 6.1.167, 6.6.130, 6.12.78, 6.18.19, 6.19.9, 7.0	Patch available	CNA

Linux VendorLinux Affected 2.6.20 and later Fixed in 5.10.253, 5.15.210, 6.1.167, 6.6.130, 6.12.78, 6.18.19, 6.19.9, 7.0 Patch available CNA

CPE configurations NVD · 3

CPE	Versions	Role	Vendor
cpe:2.3:o:linux:linux_kernel::::::::	2.6.20 to before 5.10.253; 5.11 to before 6.1.167; 6.2 to before 6.6.130; 6.7 to before 6.12.78; 6.13 to before 6.18.19; 6.19 to before 6.19.9	Vulnerable	Linux
cpe:2.3:o:linux:linux_kernel:7.0:rc1::::::	7.0 rc1	Vulnerable	Linux
cpe:2.3:o:linux:linux_kernel:7.0:rc2::::::	7.0 rc2	Vulnerable	Linux

cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions 2.6.20 to before 5.10.253; 5.11 to before 6.1.167; 6.2 to before 6.6.130; 6.7 to before 6.12.78; 6.13 to before 6.18.19; 6.19 to before 6.19.9 Vulnerable ·Linux
cpe:2.3:o:linux:linux_kernel:7.0:rc1:*:*:*:*:*:* Versions 7.0 rc1 Vulnerable ·Linux
cpe:2.3:o:linux:linux_kernel:7.0:rc2:*:*:*:*:*:* Versions 7.0 rc2 Vulnerable ·Linux

Remediation

Fix · CNA Linux (Linux) Fixed in 5.10.253, 5.15.210, 6.1.167, 6.6.130, 6.12.78, 6.18.19, 6.19.9, 7.0

Vendor assessments

Red Hat

Red Hat rating: Moderate. Red Hat's page for this CVE →

Product	Status	Plan or fix
Red Hat Enterprise Linux 10	Affected	No fix yet: Fix deferred
Red Hat Enterprise Linux 6	Affected	No fix planned: Out of support scope
Red Hat Enterprise Linux 7	Affected	No fix yet: Fix deferred
Red Hat Enterprise Linux 8	Affected	No fix yet: Fix deferred
Red Hat Enterprise Linux 9	Affected	No fix yet: Fix deferred

Timeline

2026-10-02 Threatist record created from CVE-2026-43383
2026-10-03 Alias added: GHSA-m4fq-qc69-83h9
2026-10-16 CISA SSVC decision points changed
2026-10-19 Weakness changed · CISA ADP

References

Patch 7

Other 1

https://git.kernel.org/stable/c/ff44ec94d4fc8348600a69de0a8fa1102c23bce8

TI-2025-26358 tls: fix handling of zero-length records on the rx_list KEVCVSS 3.1CRITICAL 9.8
TI-2026-38352 netfilter: bridge: make ebt_snat ARP rewrite writable KEVCVSS 3.1HIGH 8.8
TI-2013-05264 The (1) get_user and (2) put_user API functions in the Linux kernel before 3.5.5 on the… KEVCVSS 3.1HIGH 8.8
TI-2022-00125 Integer overflow in kernel KEVCVSS 3.1HIGH 8.4
TI-2013-01864 The perf_swevent_init function in kernel/events/core.c in the Linux kernel before 3.8.9… KEVCVSS 3.1HIGH 8.4
TI-2021-05514 Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACE KEVCVSS 3.1HIGH 8.3

See all 15278 →

Sources

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