CVE-2026-34344

HIGHPre-NVD 7.87.8—
EchelonGraph scoreMEDIUM confidence

Score 7.8 from GitHub Security Advisory (severity: HIGH) published 2026-05-12. the CNA's CVSS baseline 7.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: cna:microsoft, epss, ghsa
Elevated
7.8EG
EchelonGraph verdictPlan mitigationSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0.3%CVSS: 7.8Exploit: Elevated riskExposed services: Not assessed

A fix is referenced (a reference tagged "Patch", often a source commit), but no release containing it is confirmed — find the release that contains it; until it is applied, mitigate (WAF / firewall / segmentation).

Access of resource using incompatible type ('type confusion') in Windows Ancillary Function Driver for WinSock allows an authorized attacker to elevate privileges locally.

CVSS v3
7.8
EG Score
7.8HIGHmedium confidence
EG Risk
35
EG Risk 35/100

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%
EPSS PROB
0.3%
EPSS %ILE
24th
KEV
Not listed

Published

May 12, 2026

Last Modified

August 10, 2026

Advisory Details (1)

Auto-updated May 12, 2026
Fix referenced — no release confirmed yet. Sources: microsoft.
microsoftMentions a patch (unverified)

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-2026-34344

Vendor Advisories for CVE-2026-34344(1)

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

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 7× in last 7d / 23× in last 30d)

Each row is a time one of our pipelines fetched, updated or re-scored this CVE. 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. An arrow marks a change the record states ("CVSS v3 → 9.1"); EPSS and GHSA rows show the values recorded at that time, not what changed (EPSS values are rounded; hover one for the exact figures). Most recent first.

Showing the most recent 98 of 296 refreshes on record for this CVE.

A repeat, a row identical to one the same pipeline wrote less than 10 seconds earlier, is not a separate refresh and is not counted. 2 repeat rows among the latest 100 are merged into the row they repeat. The 198 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  2. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  3. 2026-10-08 17:12 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  4. 2026-10-07 23:47 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  5. 2026-10-06 15:17 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  6. 2026-10-05 17:42 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  7. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  8. 2026-10-03 14:25 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  9. 2026-10-01 19:49 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  10. 2026-09-30 15:03 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  11. 2026-09-28 13:51 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  12. 2026-09-27 13:48 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  13. 2026-09-26 15:58 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  14. 2026-09-26 00:26 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  15. 2026-09-20 20:15 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  16. 2026-09-18 19:28 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  17. 2026-09-17 19:30 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  18. 2026-09-16 14:08 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  19. 2026-09-16 05:15 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  20. 2026-09-15 03:11 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  21. 2026-09-13 16:47 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  22. 2026-09-12 15:01 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  23. 2026-09-11 14:53 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  24. 2026-09-11 09:37 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  25. 2026-09-10 09:34 UTCEPSS rescoreEPSS 0.3% · 24th percentile
Show 73 more
  1. 2026-09-08 22:00 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  2. 2026-09-06 13:47 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  3. 2026-09-04 05:06 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  4. 2026-09-02 14:12 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  5. 2026-09-01 13:53 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  6. 2026-09-01 04:39 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  7. 2026-08-30 19:17 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  8. 2026-08-30 01:22 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  9. 2026-08-28 21:41 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  10. 2026-08-27 14:25 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  11. 2026-08-26 14:46 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  12. 2026-08-25 13:49 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  13. 2026-08-23 18:19 UTCEG score recompute
  14. 2026-08-23 18:19 UTCVendor advisory
  15. 2026-08-23 18:19 UTCGHSA enrichmentGHSA-j4xq-256r-c68q · GitHub severity HIGH · GitHub CVSS 7.8
  16. 2026-08-23 00:19 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  17. 2026-08-21 23:49 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  18. 2026-08-20 22:55 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  19. 2026-08-19 17:03 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  20. 2026-08-18 13:48 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  21. 2026-08-17 13:47 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  22. 2026-08-17 10:52 UTCEG score recompute
  23. 2026-08-17 10:52 UTCVendor advisory
  24. 2026-08-17 10:52 UTCGHSA enrichmentGHSA-j4xq-256r-c68q · GitHub severity HIGH · GitHub CVSS 7.8
  25. 2026-08-16 14:56 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  26. 2026-08-16 04:14 UTCEG score recompute
  27. 2026-08-16 04:14 UTCVendor advisory
  28. 2026-08-16 04:14 UTCGHSA enrichmentGHSA-j4xq-256r-c68q · GitHub severity HIGH · GitHub CVSS 7.8
  29. 2026-08-16 02:14 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  30. 2026-08-15 01:30 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  31. 2026-08-15 00:25 UTCVendor advisory
  32. 2026-08-15 00:25 UTCGHSA enrichmentGHSA-j4xq-256r-c68q · GitHub severity HIGH · GitHub CVSS 7.8
  33. 2026-08-14 13:35 UTCVendor advisory
  34. 2026-08-14 13:35 UTCGHSA enrichmentGHSA-j4xq-256r-c68q · GitHub severity HIGH · GitHub CVSS 7.8
  35. 2026-08-14 02:45 UTCEG score recompute
  36. 2026-08-14 02:45 UTCVendor advisory
  37. 2026-08-14 02:45 UTCGHSA enrichmentGHSA-j4xq-256r-c68q · GitHub severity HIGH · GitHub CVSS 7.8
  38. 2026-08-13 22:00 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  39. 2026-08-13 03:03 UTCGHSA enrichmentGHSA-j4xq-256r-c68q · GitHub severity HIGH · GitHub CVSS 7.8
  40. 2026-08-12 16:13 UTCEG score recompute
  41. 2026-08-12 16:13 UTCVendor advisory
  42. 2026-08-12 16:13 UTCGHSA enrichmentGHSA-j4xq-256r-c68q · GitHub severity HIGH · GitHub CVSS 7.8
  43. 2026-08-12 13:50 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  44. 2026-08-11 15:42 UTCEG score recompute
  45. 2026-08-11 15:42 UTCVendor advisory
  46. 2026-08-11 15:42 UTCGHSA enrichmentGHSA-j4xq-256r-c68q · GitHub severity HIGH · GitHub CVSS 7.8
  47. 2026-08-11 02:20 UTCEG score recompute
  48. 2026-08-11 02:20 UTCVendor advisory
  49. 2026-08-11 02:20 UTCGHSA enrichmentGHSA-j4xq-256r-c68q · GitHub severity HIGH · GitHub CVSS 7.8
  50. 2026-08-11 00:00 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  51. 2026-08-10 15:30 UTCGHSA enrichmentGHSA-j4xq-256r-c68q · GitHub severity HIGH · GitHub CVSS 7.8
  52. 2026-08-10 11:32 UTCGHSA enrichmentGHSA-j4xq-256r-c68q · GitHub severity HIGH · GitHub CVSS 7.8
  53. 2026-08-09 23:46 UTCEG score recompute
  54. 2026-08-09 23:46 UTCVendor advisory
  55. 2026-08-09 23:46 UTCGHSA enrichmentGHSA-j4xq-256r-c68q · GitHub severity HIGH · GitHub CVSS 7.8
  56. 2026-08-09 13:46 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  57. 2026-08-09 12:55 UTCVendor advisory
  58. 2026-08-09 12:55 UTCGHSA enrichmentGHSA-j4xq-256r-c68q · GitHub severity HIGH · GitHub CVSS 7.8
  59. 2026-08-09 02:05 UTCVendor advisory
  60. 2026-08-09 02:05 UTCGHSA enrichmentGHSA-j4xq-256r-c68q · GitHub severity HIGH · GitHub CVSS 7.8
  61. 2026-08-08 05:02 UTCGHSA enrichmentGHSA-j4xq-256r-c68q · GitHub severity HIGH · GitHub CVSS 7.8
  62. 2026-08-07 18:12 UTCEG score recompute
  63. 2026-08-07 18:12 UTCGHSA enrichmentGHSA-j4xq-256r-c68q · GitHub severity HIGH · GitHub CVSS 7.8
  64. 2026-08-07 07:22 UTCVendor advisory
  65. 2026-08-07 07:22 UTCGHSA enrichmentGHSA-j4xq-256r-c68q · GitHub severity HIGH · GitHub CVSS 7.8
  66. 2026-08-06 19:29 UTCEG score recompute
  67. 2026-08-06 19:29 UTCVendor advisory
  68. 2026-08-06 19:29 UTCGHSA enrichmentGHSA-j4xq-256r-c68q · GitHub severity HIGH · GitHub CVSS 7.8
  69. 2026-08-06 13:46 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  70. 2026-08-06 08:39 UTCVendor advisory
  71. 2026-08-06 08:39 UTCGHSA enrichmentGHSA-j4xq-256r-c68q · GitHub severity HIGH · GitHub CVSS 7.8
  72. 2026-08-05 21:49 UTCEG score recompute
  73. 2026-08-05 21:49 UTCVendor advisory

Publicly available exploits

(1 reference)

Public exploit code is referenced for this CVE (1 GitHub PoC). Defenders should treat patch urgency accordingly.

  • GitHub PoCnhh9905/CVE-2026-34344
    Published Aug 13, 2026

    CVE 1-day in afd.sys

    Open source ↗

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-34344?
CVE-2026-34344 is a high vulnerability published on May 12, 2026. Access of resource using incompatible type ('type confusion') in Windows Ancillary Function Driver for WinSock allows an authorized attacker to elevate privileges locally.
When was the CVE record for CVE-2026-34344 published?
The CVE record for CVE-2026-34344 was published on May 12, 2026. That is the record's publication date; the vulnerability itself may have been made public earlier. EchelonGraph's copy of the record carries a last-modified date of August 10, 2026; the record at its source may have been updated since.
Is CVE-2026-34344 actively exploited?
CVE-2026-34344 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.3% probability of exploitation in the next 30 days (24th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-34344?
CVE-2026-34344 has a CVSS base score of 7.8 (the CNA's own assessment, by microsoft; NVD's own analysis pending).
How do I remediate CVE-2026-34344?
A fix for CVE-2026-34344 is referenced (a reference tagged "Patch", often a source commit), but EchelonGraph has no release containing it on record. Check that reference and the vendor's advisory for a release that contains the fix and update to it; until then, restrict network exposure of the affected system or apply the vendor's mitigation. The vendor advisories EchelonGraph has for CVE-2026-34344 are linked in the Vendor Advisories panel on this page.

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