CVE-2026-43190

HIGHNVD 8.28.2—
EchelonGraph scoreMEDIUM confidence

Score 8.2 from GitHub Security Advisory (severity: HIGH) published 2026-05-06. NVD baseline CVSS 8.2; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
8.2
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 0%CVSS: 8.2Exploit: NoneExposed: 0

A fix is available — apply it.

In the Linux kernel, the following vulnerability has been resolved:

netfilter: xt_tcpmss: check remaining length before reading optlen

Quoting reporter: In net/netfilter/xt_tcpmss.c (lines 53-68), the TCP option parser reads op[i+1] directly without validating the remaining option length.

If the last byte of the option field is not EOL/NOP (0/1), the code attempts to index op[i+1]. In the case where i + 1 == optlen, this causes an out-of-bounds read, accessing memory past the optlen boundary (either reading beyond the stack buffer _opt or the following payload).

CVSS v3
8.2
EG Score
8.2(medium)
EPSS
37.5%
KEV
Not listed

Published

May 6, 2026

Last Modified

May 11, 2026

Advisory Details (8)

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

netfilter: xt_tcpmss: check remaining length before reading optlen - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/f895191dc32c53eaf443b6443fe40945b2f92287
generic

netfilter: xt_tcpmss: check remaining length before reading optlen - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/f6c412dcfd76b0516d51aa847d8f4c7b70381b09
generic

netfilter: xt_tcpmss: check remaining length before reading optlen - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/eaedc0bc18be46fe7f58170e967959a932c4f824
generic

netfilter: xt_tcpmss: check remaining length before reading optlen - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/cd5beda7e0e32865e214f28034bb92c1cecff885
generic

netfilter: xt_tcpmss: check remaining length before reading optlen - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/8b300f726640c48c3edfe9c453334dd801f4b74e
generic

netfilter: xt_tcpmss: check remaining length before reading optlen - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/735ee8582da3d239eb0c7a53adca61b79fb228b3
generic

netfilter: xt_tcpmss: check remaining length before reading optlen - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/5e13d0a37666955b6cfddc0f73cb40ed645b8a05
generic

netfilter: xt_tcpmss: check remaining length before reading optlen - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/07a9b32eaae792ff7d0fcac14d8920c937c0a9c3

Vendor Advisories for CVE-2026-43190(12)

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

Patch Availability(8)

Vendor / EcosystemFixed in / PatchReleasedSource
redhatkernel-0:4.18.0-372.195.1.el8_62026-06-12redhat
redhatkernel-0:5.14.0-570.120.1.el9_62026-06-11redhat
redhatkernel-0:5.14.0-427.130.1.el9_42026-06-10redhat
redhatkernel-0:4.18.0-553.126.1.el8_102026-05-28redhat
redhatkernel-0:5.14.0-687.12.1.el9_82026-05-28redhat
redhatkernel-0:6.12.0-211.18.1.el10_22026-05-28redhat
redhatkernel-rt-0:4.18.0-553.126.1.rt7.467.el8_102026-05-28redhat
linuxKernel @ 5.10.252—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.

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 8× in last 7d / 31× 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 128 total refreshes for this CVE.

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

Related CVEs(same product + same vendor + same CWE)

Frequently asked(5)

What is CVE-2026-43190?
CVE-2026-43190 is a high vulnerability published on May 6, 2026. In the Linux kernel, the following vulnerability has been resolved: netfilter: xt_tcpmss: check remaining length before reading optlen Quoting reporter: In net/netfilter/xt_tcpmss.c (lines 53-68), the TCP option parser reads op[i+1] directly without validating the remaining option length. If the…
When was CVE-2026-43190 disclosed?
CVE-2026-43190 was first published in the National Vulnerability Database on May 6, 2026, with the most recent update on May 11, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-43190 actively exploited?
CVE-2026-43190 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 37.5% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-43190?
CVE-2026-43190 has a CVSS v3 base score of 8.2 (NVD).
How do I remediate CVE-2026-43190?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-43190, 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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