CVE-2026-43391

HIGHNVD 8.88.8
EchelonGraph scoreMEDIUM confidence

Score 8.8 from GitHub Security Advisory (severity: HIGH) published 2026-05-08. NVD baseline CVSS 8.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
8.8EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 8.8Exploit: 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:

nsfs: tighten permission checks for handle opening

Even privileged services should not necessarily be able to see other privileged service's namespaces so they can't leak information to each other. Use may_see_all_namespaces() helper that centralizes this policy until the nstree adapts.

CVSS v3
8.8
EG Score
8.8(medium)
EG Risk
44(Track)
EG Risk 44/100SSVC: 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
Severity88% × 45%
Exploitation0% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
2%
KEV
Not listed

Published

May 8, 2026

Last Modified

May 26, 2026

Advisory Details (2)

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

nsfs: tighten permission checks for handle opening - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/d2324a9317f00013facb0ba00b00440e19d2af5e
generic

nsfs: tighten permission checks for handle opening - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/1797ee11451f1b2be69863a9f5bd43b948813fdf

Patch Availability(1)

Vendor / EcosystemFixed in / PatchReleasedSource
linuxKernel @ 6.19.9osv

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 7× in last 7d / 27× 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 111 total refreshes for this CVE.

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

Frequently asked(5)

What is CVE-2026-43391?
CVE-2026-43391 is a high vulnerability published on May 8, 2026. In the Linux kernel, the following vulnerability has been resolved: nsfs: tighten permission checks for handle opening Even privileged services should not necessarily be able to see other privileged service's namespaces so they can't leak information to each other. Use mayseeall_namespaces() helper…
When was CVE-2026-43391 disclosed?
CVE-2026-43391 was first published in the National Vulnerability Database on May 8, 2026, with the most recent update on May 26, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-43391 actively exploited?
CVE-2026-43391 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 97.7% of all scored CVEs.
What is the CVSS score of CVE-2026-43391?
CVE-2026-43391 has a CVSS v3 base score of 8.8 (NVD).
How do I remediate CVE-2026-43391?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-43391, 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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