CVE-2026-43383

CRITICALPre-NVD 9.49.4—
EchelonGraph scoreMEDIUM confidence

Score 9.4 from GitHub Security Advisory (severity: CRITICAL) published 2026-05-08. a secondary CVSS source baseline 9.4; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
9.4EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 9.4Exploit: None knownExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

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.

CVSS v3
9.4
EG Score
9.4(medium)
EG Risk
47(Track)
EG Risk 47/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity94% × 45%
Exploitation0% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
36%
KEV
Not listed

Published

May 8, 2026

Last Modified

June 19, 2026

Advisory Details (7)

Auto-updated May 11, 2026
No patch confirmed yet.
generic

net/tcp-md5: Fix MAC comparison to be constant-time - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/b502e97e29d791ff7a8051f29a414535739be218
generic

net/tcp-md5: Fix MAC comparison to be constant-time - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/ae3831b44f477de048287493e184fc3ff913b624
generic

net/tcp-md5: Fix MAC comparison to be constant-time - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/821c8751fdeecdeecabeb11704dd33439c9e4bbc
generic

net/tcp-md5: Fix MAC comparison to be constant-time - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/5d305a95130a8d08b9545e47f1e18d29d59866cb
generic

net/tcp-md5: Fix MAC comparison to be constant-time - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/46d0d6f50dab706637f4c18a470aac20a21900d3
generic

net/tcp-md5: Fix MAC comparison to be constant-time - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/345a9530756528d7ca407663d659c3c40e75c3dd
generic

net/tcp-md5: Fix MAC comparison to be constant-time - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/02669e2a4d207068edce7e8b5fafd85822018ce6

Vendor Advisories for CVE-2026-43383(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Patch Availability(1)

Vendor / EcosystemFixed in / PatchReleasedSource
linuxKernel @ 5.10.253—osv

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Data Freshness Timeline

(refreshed 9× in last 7d / 32× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

Showing the most recent 100 of 172 total refreshes for this CVE.

  1. 2026-07-27 14:13 UTCEPSS rescore
  2. 2026-07-26 14:54 UTCEPSS rescore
  3. 2026-07-26 14:54 UTCEPSS rescore
  4. 2026-07-25 14:18 UTCEPSS rescore
  5. 2026-07-24 14:17 UTCEPSS rescore
  6. 2026-07-23 14:18 UTCEPSS rescore
  7. 2026-07-23 03:14 UTCEG score recompute
  8. 2026-07-22 14:08 UTCEPSS rescore
  9. 2026-07-21 15:24 UTCEPSS rescore
  10. 2026-07-20 17:08 UTCEPSS rescore
  11. 2026-07-19 14:31 UTCEPSS rescore
  12. 2026-07-19 02:29 UTCEPSS rescore
  13. 2026-07-18 10:04 UTCEPSS rescore
  14. 2026-07-16 17:03 UTCEPSS rescore
  15. 2026-07-16 09:53 UTCOSV refresh
  16. 2026-07-15 16:57 UTCEPSS rescore
  17. 2026-07-15 02:00 UTCEPSS rescore
  18. 2026-07-13 22:30 UTCEPSS rescore
  19. 2026-07-13 06:13 UTCEPSS rescore
  20. 2026-07-12 05:46 UTCEPSS rescore
  21. 2026-07-11 08:27 UTCEPSS rescore
  22. 2026-07-09 19:10 UTCEPSS rescore
  23. 2026-07-08 15:16 UTCEPSS rescore
  24. 2026-07-07 13:46 UTCEPSS rescore
  25. 2026-07-06 16:27 UTCEPSS rescore
Show 75 more
  1. 2026-07-06 02:23 UTCEPSS rescore
  2. 2026-07-05 02:30 UTCEPSS rescore
  3. 2026-07-04 06:31 UTCEPSS rescore
  4. 2026-07-01 15:06 UTCEPSS rescore
  5. 2026-06-30 23:22 UTCEPSS rescore
  6. 2026-06-29 14:06 UTCEPSS rescore
  7. 2026-06-28 14:07 UTCEPSS rescore
  8. 2026-06-28 08:55 UTCGHSA enrichment
  9. 2026-06-28 04:56 UTCGHSA enrichment
  10. 2026-06-28 04:56 UTCEPSS rescore
  11. 2026-06-27 13:30 UTCGHSA enrichment
  12. 2026-06-27 03:08 UTCEPSS rescore
  13. 2026-06-26 21:26 UTCGHSA enrichment
  14. 2026-06-25 13:49 UTCEPSS rescore
  15. 2026-06-25 13:49 UTCEPSS rescore
  16. 2026-06-24 14:05 UTCEPSS rescore
  17. 2026-06-23 21:33 UTCEPSS rescore
  18. 2026-06-22 14:25 UTCEPSS rescore
  19. 2026-06-22 14:25 UTCEPSS rescore
  20. 2026-06-21 14:56 UTCEPSS rescore
  21. 2026-06-21 14:56 UTCEPSS rescore
  22. 2026-06-21 01:59 UTCEPSS rescore
  23. 2026-06-19 19:25 UTCEPSS rescore
  24. 2026-06-18 17:52 UTCEPSS rescore
  25. 2026-06-18 17:52 UTCEPSS rescore
  26. 2026-06-17 17:53 UTCEPSS rescore
  27. 2026-06-17 05:50 UTCGHSA enrichment
  28. 2026-06-17 01:48 UTCGHSA enrichment
  29. 2026-06-16 17:52 UTCEPSS rescore
  30. 2026-06-15 17:49 UTCEPSS rescore
  31. 2026-06-15 05:44 UTCGHSA enrichment
  32. 2026-06-15 02:05 UTCGHSA enrichment
  33. 2026-06-14 22:22 UTCGHSA enrichment
  34. 2026-06-14 18:30 UTCGHSA enrichment
  35. 2026-06-14 14:51 UTCGHSA enrichment
  36. 2026-06-14 10:43 UTCGHSA enrichment
  37. 2026-06-14 06:46 UTCGHSA enrichment
  38. 2026-06-14 02:51 UTCGHSA enrichment
  39. 2026-06-13 23:00 UTCEPSS rescore
  40. 2026-06-12 23:50 UTCGHSA enrichment
  41. 2026-06-12 23:12 UTCEPSS rescore
  42. 2026-06-12 23:12 UTCEPSS rescore
  43. 2026-06-12 20:12 UTCGHSA enrichment
  44. 2026-06-12 11:36 UTCGHSA enrichment
  45. 2026-06-12 07:57 UTCGHSA enrichment
  46. 2026-06-12 04:18 UTCGHSA enrichment
  47. 2026-06-12 00:27 UTCGHSA enrichment
  48. 2026-06-11 20:48 UTCGHSA enrichment
  49. 2026-06-11 17:10 UTCGHSA enrichment
  50. 2026-06-11 14:00 UTCEPSS rescore
  51. 2026-06-11 12:01 UTCGHSA enrichment
  52. 2026-06-11 08:16 UTCGHSA enrichment
  53. 2026-06-11 04:21 UTCGHSA enrichment
  54. 2026-06-11 00:32 UTCGHSA enrichment
  55. 2026-06-10 22:18 UTCEPSS rescore
  56. 2026-06-10 20:40 UTCGHSA enrichment
  57. 2026-06-10 17:00 UTCGHSA enrichment
  58. 2026-06-10 13:22 UTCEPSS rescore
  59. 2026-06-10 13:22 UTCEPSS rescore
  60. 2026-06-10 13:19 UTCGHSA enrichment
  61. 2026-06-10 09:40 UTCGHSA enrichment
  62. 2026-06-10 06:02 UTCGHSA enrichment
  63. 2026-06-10 02:23 UTCGHSA enrichment
  64. 2026-06-09 22:44 UTCGHSA enrichment
  65. 2026-06-09 18:39 UTCGHSA enrichment
  66. 2026-06-09 15:00 UTCGHSA enrichment
  67. 2026-06-09 11:21 UTCGHSA enrichment
  68. 2026-06-09 07:41 UTCGHSA enrichment
  69. 2026-06-09 04:02 UTCGHSA enrichment
  70. 2026-06-09 00:23 UTCGHSA enrichment
  71. 2026-06-08 20:44 UTCGHSA enrichment
  72. 2026-06-08 14:17 UTCEPSS rescore
  73. 2026-06-08 14:17 UTCEPSS rescore
  74. 2026-06-08 13:01 UTCGHSA enrichment
  75. 2026-06-08 09:22 UTCGHSA enrichment

Related CVEs(same product)

Frequently asked(5)

What is CVE-2026-43383?
CVE-2026-43383 is a critical vulnerability published on May 8, 2026. 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.
When was CVE-2026-43383 disclosed?
CVE-2026-43383 was first published in the National Vulnerability Database on May 8, 2026, with the most recent update on June 19, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-43383 actively exploited?
CVE-2026-43383 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 63.8% of all scored CVEs.
What is the CVSS score of CVE-2026-43383?
CVE-2026-43383 has a CVSS v3 base score of 9.4 (NVD).
How do I remediate CVE-2026-43383?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-43383, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

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