CVE-2026-42991

HIGHPre-NVD 7.87.8—
EchelonGraph scoreMEDIUM confidence

Score 7.8 from GitHub Security Advisory (severity: HIGH) published 2026-06-09. the CNA's CVSS baseline 7.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: cna:microsoft, epss, ghsa
Trending — 4 sources updated this week
7.8EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 7.8Exploit: None knownExposed: 0

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

Concurrent execution using shared resource with improper synchronization ('race condition') in Windows Push Notifications allows an authorized attacker to elevate privileges locally.

CVSS v3
7.8
EG Score
7.8(medium)
EG Risk
35(Track)
EG Risk 35/100SSVC: 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
Severity78% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
7%
KEV
Not listed

Published

June 9, 2026

Last Modified

August 25, 2026

Advisory Details (1)

Auto-updated Jun 9, 2026
Patch available. Sources: microsoft.
microsoft Patch Available

Security Update Guide - Microsoft Security Response Center

Security Update Guide - Microsoft Security Response Center. Patch available via Microsoft Security Update

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-42991

Vendor Advisories for CVE-2026-42991(2)

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

Weakness Classification(2)

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

Data Freshness Timeline

(refreshed 9× in last 7d / 55× 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 344 total refreshes for this CVE.

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

Frequently asked(5)

What is CVE-2026-42991?
CVE-2026-42991 is a high vulnerability published on June 9, 2026. Concurrent execution using shared resource with improper synchronization ('race condition') in Windows Push Notifications allows an authorized attacker to elevate privileges locally.
When was CVE-2026-42991 disclosed?
CVE-2026-42991 was first published in the National Vulnerability Database on June 9, 2026, with the most recent update on August 25, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-42991 actively exploited?
CVE-2026-42991 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 93.1% of all scored CVEs.
What is the CVSS score of CVE-2026-42991?
CVE-2026-42991 has a CVSS v4.0 base score of 7.8 (CNA self-assessment; NVD's own analysis pending).
How do I remediate CVE-2026-42991?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-42991, 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

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