CVE-2026-55031

HIGHPre-NVD 7.87.8—
EchelonGraph scoreMEDIUM confidence

Score 7.8 from GitHub Security Advisory (severity: HIGH) published 2026-07-14. 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.

Out-of-bounds read in Microsoft Office Excel allows an unauthorized attacker to execute code 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
38%
KEV
Not listed

Published

July 14, 2026

Last Modified

August 28, 2026

Advisory Details (1)

Auto-updated Jul 15, 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-2026-55031

Vendor Advisories for CVE-2026-55031(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 35× in last 7d / 177× 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 249 total refreshes for this CVE.

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

Frequently asked(5)

What is CVE-2026-55031?
CVE-2026-55031 is a high vulnerability published on July 14, 2026. Out-of-bounds read in Microsoft Office Excel allows an unauthorized attacker to execute code locally.
When was CVE-2026-55031 disclosed?
CVE-2026-55031 was first published in the National Vulnerability Database on July 14, 2026, with the most recent update on August 28, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-55031 actively exploited?
CVE-2026-55031 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 61.5% of all scored CVEs.
What is the CVSS score of CVE-2026-55031?
CVE-2026-55031 has a CVSS v4.0 base score of 7.8 (CNA self-assessment; NVD's own analysis pending).
How do I remediate CVE-2026-55031?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-55031, 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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