CVE-2026-43040

HIGHNVD 7.17.1
EchelonGraph scoreMEDIUM confidence

Score 7.1 from GitHub Security Advisory (severity: HIGH) published 2026-05-01. NVD baseline CVSS 7.1; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
7.1
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 0%CVSS: 7.1Exploit: NoneExposed: 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: ipv6: ndisc: fix ndisc_ra_useropt to initialize nduseropt_padX fields to zero to prevent an info-leak

When processing Router Advertisements with user options the kernel builds an RTM_NEWNDUSEROPT netlink message. The nduseroptmsg struct has three padding fields that are never zeroed and can leak kernel data

The fix is simple, just zeroes the padding fields.

CVSS v3
7.1
EG Score
7.1(medium)
EG Risk
EPSS
2.4%
KEV
Not listed

Published

May 1, 2026

Last Modified

July 14, 2026

Advisory Details (8)

Auto-updated May 8, 2026
No patch confirmed yet.
generic

net: ipv6: ndisc: fix ndisc_ra_useropt to initialize nduseropt_padX fields to zero to prevent an info-leak - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/ef3645606e4a635d5062a492f22b7f490852ee67
generic

net: ipv6: ndisc: fix ndisc_ra_useropt to initialize nduseropt_padX fields to zero to prevent an info-leak - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/b485eef3d97b7aae55ce669b6de555ec81f3d21c
generic

net: ipv6: ndisc: fix ndisc_ra_useropt to initialize nduseropt_padX fields to zero to prevent an info-leak - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/ae05340ccaa9d347fe85415609e075545bec589f
generic

net: ipv6: ndisc: fix ndisc_ra_useropt to initialize nduseropt_padX fields to zero to prevent an info-leak - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/7f56d87e527bb5a13c3e8b0d5840cb6332822f6d
generic

net: ipv6: ndisc: fix ndisc_ra_useropt to initialize nduseropt_padX fields to zero to prevent an info-leak - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/4f810c686fde509d1cdaa706322d9d2531f8f1a4
generic

net: ipv6: ndisc: fix ndisc_ra_useropt to initialize nduseropt_padX fields to zero to prevent an info-leak - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/2fe4d0ba690a69ad6ae9f7ab9bdc96e02610b648
generic

net: ipv6: ndisc: fix ndisc_ra_useropt to initialize nduseropt_padX fields to zero to prevent an info-leak - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/1da9023f6b071a38e5430ffbce4b70b2b1ac4f9c
generic

net: ipv6: ndisc: fix ndisc_ra_useropt to initialize nduseropt_padX fields to zero to prevent an info-leak - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/11d7fe97421cfc81549940c20ed5ac9472d6db05

Vendor Advisories for CVE-2026-43040(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 @ 5.10.253osv

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 / 28× 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.

  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 11:04 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. 2026-07-14 13:19 UTCNVD updateCVSS v3 → 7.1 · severity → HIGH
  11. 2026-07-14 13:11 UTCMITRE cvelistV5
  12. 2026-07-13 22:30 UTCEPSS rescore
  13. 2026-07-11 08:27 UTCEPSS rescore
  14. 2026-07-09 19:10 UTCEPSS rescore
  15. 2026-07-08 15:16 UTCEPSS rescore
  16. 2026-07-07 13:46 UTCEPSS rescore
  17. 2026-07-06 16:27 UTCEPSS rescore
  18. 2026-07-06 02:23 UTCEPSS rescore
  19. 2026-07-05 02:30 UTCEPSS rescore
  20. 2026-07-04 06:31 UTCEPSS rescore
  21. 2026-07-01 15:06 UTCEPSS rescore
  22. 2026-06-30 23:22 UTCEPSS rescore
  23. 2026-06-29 14:06 UTCEPSS rescore
  24. 2026-06-28 14:07 UTCEPSS rescore
  25. 2026-06-27 03:08 UTCEPSS rescore
Show 74 more
  1. 2026-06-25 13:49 UTCEPSS rescore
  2. 2026-06-25 13:49 UTCEPSS rescore
  3. 2026-06-24 14:05 UTCEPSS rescore
  4. 2026-06-22 14:25 UTCEPSS rescore
  5. 2026-06-22 14:25 UTCEPSS rescore
  6. 2026-06-21 14:56 UTCEPSS rescore
  7. 2026-06-21 14:56 UTCEPSS rescore
  8. 2026-06-21 01:59 UTCEPSS rescore
  9. 2026-06-19 19:25 UTCEPSS rescore
  10. 2026-06-18 17:52 UTCEPSS rescore
  11. 2026-06-18 17:52 UTCEPSS rescore
  12. 2026-06-17 17:53 UTCEPSS rescore
  13. 2026-06-16 17:52 UTCEPSS rescore
  14. 2026-06-15 17:49 UTCEPSS rescore
  15. 2026-06-14 21:31 UTCGHSA enrichment
  16. 2026-06-14 08:49 UTCGHSA enrichment
  17. 2026-06-13 23:00 UTCEPSS rescore
  18. 2026-06-12 23:12 UTCEPSS rescore
  19. 2026-06-12 23:12 UTCEPSS rescore
  20. 2026-06-12 06:04 UTCGHSA enrichment
  21. 2026-06-11 17:22 UTCGHSA enrichment
  22. 2026-06-11 14:00 UTCEPSS rescore
  23. 2026-06-11 03:23 UTCGHSA enrichment
  24. 2026-06-10 22:18 UTCEPSS rescore
  25. 2026-06-10 13:22 UTCEPSS rescore
  26. 2026-06-10 13:22 UTCEPSS rescore
  27. 2026-06-10 13:18 UTCGHSA enrichment
  28. 2026-06-10 00:37 UTCGHSA enrichment
  29. 2026-06-09 11:56 UTCGHSA enrichment
  30. 2026-06-08 23:14 UTCGHSA enrichment
  31. 2026-06-08 14:17 UTCEPSS rescore
  32. 2026-06-08 14:17 UTCEPSS rescore
  33. 2026-06-08 07:20 UTCGHSA enrichment
  34. 2026-06-07 18:39 UTCGHSA enrichment
  35. 2026-06-07 15:25 UTCEPSS rescore
  36. 2026-06-07 15:25 UTCEPSS rescore
  37. 2026-06-07 05:58 UTCGHSA enrichment
  38. 2026-06-06 17:17 UTCGHSA enrichment
  39. 2026-06-06 13:47 UTCEPSS rescore
  40. 2026-06-06 13:47 UTCEPSS rescore
  41. 2026-06-06 04:35 UTCGHSA enrichment
  42. 2026-06-05 22:47 UTCEPSS rescore
  43. 2026-06-05 15:54 UTCGHSA enrichment
  44. 2026-06-05 03:13 UTCGHSA enrichment
  45. 2026-06-04 14:30 UTCGHSA enrichment
  46. 2026-06-04 13:12 UTCEPSS rescore
  47. 2026-06-04 13:12 UTCEPSS rescore
  48. 2026-06-04 01:46 UTCGHSA enrichment
  49. 2026-06-03 13:04 UTCGHSA enrichment
  50. 2026-06-03 00:23 UTCGHSA enrichment
  51. 2026-06-02 20:13 UTCEPSS rescore
  52. 2026-06-02 11:42 UTCGHSA enrichment
  53. 2026-06-01 23:01 UTCGHSA enrichment
  54. 2026-06-01 13:52 UTCEPSS rescore
  55. 2026-06-01 13:52 UTCEPSS rescore
  56. 2026-06-01 10:20 UTCGHSA enrichment
  57. 2026-05-31 22:30 UTCEPSS rescore
  58. 2026-05-31 22:30 UTCEPSS rescore
  59. 2026-05-31 00:16 UTCEPSS rescore
  60. 2026-05-31 00:16 UTCEPSS rescore
  61. 2026-05-29 13:44 UTCEPSS rescore
  62. 2026-05-29 13:44 UTCEPSS rescore
  63. 2026-05-28 13:44 UTCEPSS rescore
  64. 2026-05-28 13:44 UTCEPSS rescore
  65. 2026-05-27 13:40 UTCEPSS rescore
  66. 2026-05-27 13:40 UTCEPSS rescore
  67. 2026-05-26 13:44 UTCEPSS rescore
  68. 2026-05-26 07:18 UTCEPSS rescore
  69. 2026-05-20 22:38 UTCEPSS rescore
  70. 2026-05-20 22:38 UTCEPSS rescore
  71. 2026-05-20 14:50 UTCEG score recompute
  72. 2026-05-20 14:50 UTCGHSA enrichment
  73. 2026-05-20 11:22 UTCEPSS rescore
  74. 2026-05-20 11:22 UTCEPSS rescore

Frequently asked(5)

What is CVE-2026-43040?
CVE-2026-43040 is a high vulnerability published on May 1, 2026. In the Linux kernel, the following vulnerability has been resolved: net: ipv6: ndisc: fix ndiscrauseropt to initialize nduseropt_padX fields to zero to prevent an info-leak When processing Router Advertisements with user options the kernel builds an RTM_NEWNDUSEROPT netlink message. The…
When was CVE-2026-43040 disclosed?
CVE-2026-43040 was first published in the National Vulnerability Database on May 1, 2026, with the most recent update on July 14, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-43040 actively exploited?
CVE-2026-43040 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 2.4% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-43040?
CVE-2026-43040 has a CVSS v3 base score of 7.1 (NVD).
How do I remediate CVE-2026-43040?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-43040, 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.

Dependency Blast Radius

Explore the affected products and dependency analysis for CVE-2026-43040

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