CVE-2026-65400

CRITICALPre-NVD 9.89.8—
EchelonGraph scoreHIGH confidence

Score elevated to 9.8 because this CVE is listed on the CISA Known Exploited Vulnerabilities catalog (added 2026-08-18), indicating real-world exploitation has been confirmed by US federal agencies. CISA-ADP (Vulnrichment) CVSS v3.1 baseline 9.8 retained for reference (NVD's own analysis pending). Confidence: HIGH.

Triggered by: CISA KEV (actively exploited)
Sources: cisa-adp, cisa_kev, epss, ghsa
Trending — 3 sources updated this weekExploited in the wild
9.8EG
EchelonGraph verdictPatch nowTreat as an emergency — this is being exploited.
  • Actively exploited in the wild (CISA-KEV)
CISA-KEV: ExploitedEPSS PROB: 1.7%CVSS: 9.8Exploit: cisa kev · ssvc active · public exploitExposed services: Not assessed

A fix is available — apply it.

An authentication issue was addressed with improved state management. This issue is fixed in macOS Golden Gate 27, macOS Sequoia 15.7.9, macOS Sonoma 14.8.9, macOS Tahoe 26.6.1, macOS Tahoe 26.7. An attacker on the network may be able to authenticate to Screen Sharing without valid credentials.

CVSS v3
9.8
EG Score
9.8CRITICALhigh confidence
EG Risk
99
EG Risk 99/100CISA 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
Severity98% × 45%
Exploitation100% × 40%
Automatability100% × 15%
CISA SSVC: Attend at low mission impact; Act at medium or high.
Action: A fix is available. Apply it sooner than your standard update timelines at low mission impact and as soon as possible at medium or high.
EPSS PROB
1.7%
EPSS %ILE
76th
KEV
⚠ Exploited

CISA SSVCAttend at low mission impact; Act at medium or high.

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

Exploitation active (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 6, 2026

Last Modified

September 15, 2026

Advisory Details (9)

Auto-updated Sep 29, 2026
⚠️ Active exploitation confirmed. Patch available. Sources: cisa.
cisa Patch Available🔴 Active Exploitation

Known Exploited Vulnerabilities Catalog | CISA

Known Exploited Vulnerabilities Catalog | CISA. Listed in CISA Known Exploited Vulnerabilities catalog.

https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-65400
generic

NCSC NL | Security Advisories

https://advisories.ncsc.nl/2026/ncsc-2026-0280.html
generic

Full Disclosure: APPLE-SA-08-06-2026-2 macOS Sequoia 15.7.9

http://seclists.org/fulldisclosure/2026/Aug/37
generic

Full Disclosure: APPLE-SA-08-06-2026-3 macOS Sonoma 14.8.9

http://seclists.org/fulldisclosure/2026/Aug/36
generic

About the security content of macOS Tahoe 26.7 - Apple Support

https://support.apple.com/en-us/149042
generic

About the security content of macOS Golden Gate 27 - Apple Support

https://support.apple.com/en-us/149035
generic

About the security content of macOS Sonoma 14.8.9 - Apple Support

https://support.apple.com/en-us/148172
generic

About the security content of macOS Sequoia 15.7.9 - Apple Support

https://support.apple.com/en-us/148171
generic

About the security content of macOS Tahoe 26.6.1 - Apple Support

https://support.apple.com/en-us/148170

Vendor Advisories for CVE-2026-65400(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 57× in last 7d / 248× 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 483 total refreshes for this CVE.

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

Publicly available exploits

(3 references)

Working exploit code is in the public domain (3 GitHub PoCs). Defenders should treat patch urgency accordingly — public PoCs typically lead to mass-exploitation within 24-72 hours.

  • GitHub PoCacheong08/CVE-2026-65400
    First seen Aug 22, 2026

    Apple MacOS Screen Sharing Arbitrary File read/write -> RCE

    Open source ↗
  • GitHub PoCpanchocosil/CVE-2026-65400-poc
    First seen Aug 21, 2026

    Read-only PoC for CVE-2026-65400 — macOS Screen Sharing (screensharingd) pre-auth SRP bypass giving root file read. Patched in macOS 26.6.1 / 15.7.9 / 14.8.9.

    Open source ↗
  • GitHub PoCHORKimhab/CVE-2026-65400
    First seen Aug 18, 2026

    CVE-2026-65400 - Draft or TODO

    Open source ↗

Related CVEs(same CWE)

Frequently asked(6)

What is CVE-2026-65400?
CVE-2026-65400 is a critical vulnerability published on August 6, 2026. An authentication issue was addressed with improved state management. This issue is fixed in macOS Golden Gate 27, macOS Sequoia 15.7.9, macOS Sonoma 14.8.9, macOS Tahoe 26.6.1, macOS Tahoe 26.7. An attacker on the network may be able to authenticate to Screen Sharing without valid credentials.
When was CVE-2026-65400 disclosed?
CVE-2026-65400 was first published on August 6, 2026, with the most recent update on September 15, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-65400 actively exploited?
Yes. CISA added CVE-2026-65400 to the Known Exploited Vulnerabilities catalog on August 18, 2026, affecting Apple macOS. KEV listing indicates confirmed exploitation in the wild; this CVE warrants immediate attention. A fix is available. Apply it.
What is the CVSS score of CVE-2026-65400?
CVE-2026-65400 has a CVSS v3.1 base score of 9.8 (CISA-ADP / Vulnrichment enrichment; NVD's own analysis pending).
Which products are affected by CVE-2026-65400?
CVE-2026-65400 affects Apple macOS.
How do I remediate CVE-2026-65400?
A fix for CVE-2026-65400 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-65400 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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