CVE-2026-65801

CRITICALPre-NVD 10.010.0—
EchelonGraph scoreMEDIUM confidence

Score 10.0 from GitHub Security Advisory (severity: CRITICAL) published 2026-08-21. The CNA's CVSS baseline 10.0; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: cna:microsoft, epss, ghsa
Trending — 4 sources updated this week
10.0EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0.9%CVSS: 10.0Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

Server-side request forgery (ssrf) in Microsoft Exchange Online allows an unauthorized attacker to elevate privileges over a network.

CVSS v3
10.0
EG Score
10.0CRITICALmedium confidence
EG Risk
60
EG Risk 60/100CISA SSVC

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
Severity100% × 45%
Exploitation1% × 40%
Automatability100% × 15%
CISA SSVC: Track at low or medium mission impact; Attend at high (mission-essential systems).
Action: A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.
EPSS PROB
0.9%
EPSS %ILE
58th
KEV
Not listed

CISA SSVCTrack at low or medium mission impact; Attend at high (mission-essential systems).

A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.

Exploitation none (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). Mission impact is CISA's Mission & Well-being decision point, and only you can judge it: high means the affected system is essential to your organisation's mission, or its compromise could cause irreversible harm to people. CISA's decision table

Published

August 20, 2026

Last Modified

September 29, 2026

Advisory Details (1)

Auto-updated Sep 29, 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-2026-65801

Vendor Advisories for CVE-2026-65801(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 72× in last 7d / 333× 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 557 total refreshes for this CVE.

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

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-65801?
CVE-2026-65801 is a critical vulnerability published on August 20, 2026. Server-side request forgery (ssrf) in Microsoft Exchange Online allows an unauthorized attacker to elevate privileges over a network.
When was CVE-2026-65801 disclosed?
CVE-2026-65801 was first published on August 20, 2026, with the most recent update on September 29, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-65801 actively exploited?
CVE-2026-65801 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.9% probability of exploitation in the next 30 days (58th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-65801?
CVE-2026-65801 has a CVSS base score of 10.0 (the CNA's own assessment, by microsoft; NVD's own analysis pending).
How do I remediate CVE-2026-65801?
A fix for CVE-2026-65801 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-65801 are linked in the Vendor Advisories panel on this page.

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