CVE-2026-65661

HIGHPre-NVD 7.87.8—
EchelonGraph scoreHIGH confidence

Score 7.8 from GitHub Security Advisory (severity: HIGH) published 2026-08-11. 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.

Heap-based buffer overflow in Microsoft Office allows an unauthorized attacker to execute code locally.

CVSS v3
7.8
EG Score
7.8(high)
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
26%
KEV
Not listed

Published

August 11, 2026

Last Modified

August 20, 2026

Advisory Details (1)

Auto-updated Aug 11, 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-2026-65661

Vendor Advisories for CVE-2026-65661(2)

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 80× in last 7d / 129× 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 129 total refreshes for this CVE.

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

Related CVEs(same vendor + same CWE)

Frequently asked(5)

What is CVE-2026-65661?
CVE-2026-65661 is a high vulnerability published on August 11, 2026. Heap-based buffer overflow in Microsoft Office allows an unauthorized attacker to execute code locally.
When was CVE-2026-65661 disclosed?
CVE-2026-65661 was first published in the National Vulnerability Database on August 11, 2026, with the most recent update on August 20, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-65661 actively exploited?
CVE-2026-65661 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 74.5% of all scored CVEs.
What is the CVSS score of CVE-2026-65661?
CVE-2026-65661 has a CVSS v4.0 base score of 7.8 (CNA self-assessment; NVD's own analysis pending).
How do I remediate CVE-2026-65661?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-65661, 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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