CVE-2026-65400

CRITICALPre-NVD 9.89.8
EchelonGraph scoreHIGH confidence

“—” beside the score: it is equal to the CVSS score beside it.

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 (Vulnrichment) CVSS v3.1, CISA Known Exploited Vulnerabilities catalog, EPSS, GitHub Security Advisory
Trending — 3 sources updated this weekExploited in the wild

Also known asEUVD-2026-54216 (ENISA EUVD) · GHSA-cwph-f4w9-f4wq (GitHub Security Advisories)Source: ENISA EUVD

9.8EG
EchelonGraph verdictPatch nowTreat as an emergency — this is being exploited.
  • Actively exploited in the wild (CISA-KEV) — the reason this is sooner than the SSVC decision on this page at low mission impact
CISA-KEV: ExploitedEPSS PROB: 1.7%CVSS: 9.8Exploit: Public PoCExposed services: Not assessed

The CVE record names the fixed release — 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 99/100

EG Risk is EchelonGraph's 0–100 priority score. It fuses impact severity (EG Severity, the CVSS base score, never the KEV-floored or EPSS-lifted EG Score) with real-world exploitation and automatability, under weights EchelonGraph set by hand, so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner.

How it’s computed (value × EchelonGraph’s weight)
Severity98% × 45%
Impact severity (EG Severity): CVSS 9.8 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation100% × 40%
Fixed at 100% for a CISA KEV listing: EchelonGraph's rule.
Automatability100% × 15%
CISA's SSVC Automatable value: yes (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Attend at low mission impact; Act at medium or high.
Exploitation active (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE.
Action: The CVE record names the fixed release. 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
77th
KEV
⚠ Exploited

What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)

The EG score (9.8): severity, escalated by confirmed exploitation. This CVE's 9.8 is its impact severity (EG Severity), not escalated.

EG Severity
9.8 CRITICALCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.CISA-ADP (Vulnrichment) CVSS v3.1 · CVSS v3.1
EG Likelihood
1.7% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-11-01). FIRST's exploitation probability, not an EchelonGraph model.
Confirmed exploitation
CISA KEV and EG-KEV Tier 1 (exploited in the wild)Reported apart from the likelihood: an observed fact, not a probability.
EG Priority
SSVC Act at medium mission impactAttend at low mission impact; Act at medium or high.CISA BOD 26-04: 3 days & forensic triage if the affected system is publicly exposed; 3 days & forensic triage if it is not.Each input and its source, and whom BOD 26-04 binds: the SSVC and BOD 26-04 blocks below.

SSVC (CISA's decision table, applied by EchelonGraph)Attend at low mission impact; Act at medium or high.

The CVE record names the fixed release. 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). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table

BOD 26-04 (CISA's remediation timeline, Table 1)3 days & forensic triage if the affected system is publicly exposed; 3 days & forensic triage if it is not.

The score's inputs: In CISA KEV yes (CISA's KEV catalog) · Automatable yes (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it

CISA required action“Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.”

Quoted verbatim from CISA's Known Exploited Vulnerabilities catalog. CISA directs it at US federal civilian executive branch agencies under Binding Operational Directive (BOD) 26-04, which replaced BOD 22-01 on 10 June 2026; it is not EchelonGraph's advice. CISA's notes: https://support.apple.com/en-us/148170 · https://support.apple.com/en-us/148171 · https://support.apple.com/en-us/148172 · https://www.cisa.gov/news-events/directives/bod-26-04-prioritizing-security-updates-based-risk · https://www.cisa.gov/news-events/directives/bod-26-04-implementation-guidance-prioritizing-security-updates-based-risk · https://nvd.nist.gov/vuln/detail/CVE-2026-65400

Published

August 6, 2026

Last Modified

October 26, 2026

Advisory Details (9)

Auto-updated Oct 26, 2026
⚠️ Actively exploited (CISA KEV, CISA Vulnrichment). Fix named in the CVE record. Sources: cisa.
Web page

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

http://seclists.org/fulldisclosure/2026/Aug/37
Web page

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

http://seclists.org/fulldisclosure/2026/Aug/36
CISA🔴 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
Web page

NCSC NL | Security Advisories

https://advisories.ncsc.nl/2026/ncsc-2026-0280.html
Web page

About the security content of macOS Tahoe 26.7 - Apple Support

https://support.apple.com/en-us/149042
Web page

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

https://support.apple.com/en-us/149035
Web page

About the security content of macOS Sonoma 14.8.9 - Apple Support

https://support.apple.com/en-us/148172
Web page

About the security content of macOS Sequoia 15.7.9 - Apple Support

https://support.apple.com/en-us/148171
Web page

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 22× in last 7d / 140× 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 100 of 606 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. None are among the latest 100 rows. The 506 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-11-01 22:51 UTCEG score recompute
  2. 2026-11-01 22:51 UTCGHSA enrichmentGHSA-cwph-f4w9-f4wq · GitHub severity HIGH · GitHub CVSS 7.1
  3. 2026-11-01 16:35 UTCEPSS rescoreEPSS 1.7% · 77th percentile
  4. 2026-10-31 22:32 UTCEG score recompute
  5. 2026-10-31 22:32 UTCGHSA enrichmentGHSA-cwph-f4w9-f4wq · GitHub severity HIGH · GitHub CVSS 7.1
  6. 2026-10-31 16:33 UTCEPSS rescoreEPSS 1.7% · 77th percentile
  7. 2026-10-30 22:14 UTCEG score recompute
  8. 2026-10-30 22:14 UTCGHSA enrichmentGHSA-cwph-f4w9-f4wq · GitHub severity HIGH · GitHub CVSS 7.1
  9. 2026-10-30 16:35 UTCEPSS rescoreEPSS 1.7% · 77th percentile
  10. 2026-10-29 21:53 UTCEG score recompute
  11. 2026-10-29 21:53 UTCGHSA enrichmentGHSA-cwph-f4w9-f4wq · GitHub severity HIGH · GitHub CVSS 7.1
  12. 2026-10-29 16:33 UTCEPSS rescoreEPSS 1.7% · 77th percentile
  13. 2026-10-28 21:34 UTCEG score recompute
  14. 2026-10-28 21:34 UTCGHSA enrichmentGHSA-cwph-f4w9-f4wq · GitHub severity HIGH · GitHub CVSS 7.1
  15. 2026-10-28 16:33 UTCEPSS rescoreEPSS 1.7% · 77th percentile
  16. 2026-10-27 21:15 UTCEG score recompute
  17. 2026-10-27 21:15 UTCGHSA enrichmentGHSA-cwph-f4w9-f4wq · GitHub severity HIGH · GitHub CVSS 7.1
  18. 2026-10-27 16:32 UTCEPSS rescoreEPSS 1.7% · 77th percentile
  19. 2026-10-26 20:56 UTCGHSA enrichmentGHSA-cwph-f4w9-f4wq · GitHub severity HIGH · GitHub CVSS 7.1
  20. 2026-10-26 17:05 UTCEG score recompute
  21. 2026-10-26 17:05 UTCGHSA enrichmentGHSA-cwph-f4w9-f4wq · GitHub severity HIGH · GitHub CVSS 7.1
  22. 2026-10-26 16:32 UTCEPSS rescoreEPSS 1.7% · 77th percentile
  23. 2026-10-25 16:45 UTCEG score recompute
  24. 2026-10-25 16:45 UTCGHSA enrichmentGHSA-cwph-f4w9-f4wq · GitHub severity HIGH · GitHub CVSS 7.1
  25. 2026-10-25 16:33 UTCEPSS rescoreEPSS 1.7% · 77th percentile
Show 75 more
  1. 2026-10-25 14:12 UTCEG score recompute
  2. 2026-10-24 16:33 UTCEPSS rescoreEPSS 1.7% · 77th percentile
  3. 2026-10-24 16:26 UTCGHSA enrichmentGHSA-cwph-f4w9-f4wq · GitHub severity HIGH · GitHub CVSS 7.1
  4. 2026-10-23 21:26 UTCEG score recompute
  5. 2026-10-23 21:26 UTCGHSA enrichmentGHSA-cwph-f4w9-f4wq · GitHub severity HIGH · GitHub CVSS 7.1
  6. 2026-10-23 16:32 UTCEPSS rescoreEPSS 1.7% · 77th percentile
  7. 2026-10-23 10:14 UTCEG score recompute
  8. 2026-10-23 10:14 UTCGHSA enrichmentGHSA-cwph-f4w9-f4wq · GitHub severity HIGH · GitHub CVSS 7.1
  9. 2026-10-22 16:35 UTCEPSS rescoreEPSS 1.7% · 77th percentile
  10. 2026-10-22 09:54 UTCEG score recompute
  11. 2026-10-22 09:54 UTCGHSA enrichmentGHSA-cwph-f4w9-f4wq · GitHub severity HIGH · GitHub CVSS 7.1
  12. 2026-10-21 16:33 UTCEPSS rescoreEPSS 1.7% · 77th percentile
  13. 2026-10-21 09:34 UTCEG score recompute
  14. 2026-10-21 09:34 UTCGHSA enrichmentGHSA-cwph-f4w9-f4wq · GitHub severity HIGH · GitHub CVSS 7.1
  15. 2026-10-20 16:33 UTCEPSS rescoreEPSS 1.7% · 77th percentile
  16. 2026-10-20 09:14 UTCEG score recompute
  17. 2026-10-20 09:13 UTCGHSA enrichmentGHSA-cwph-f4w9-f4wq · GitHub severity HIGH · GitHub CVSS 7.1
  18. 2026-10-19 16:32 UTCEPSS rescoreEPSS 1.7% · 77th percentile
  19. 2026-10-19 08:54 UTCEG score recompute
  20. 2026-10-19 08:54 UTCGHSA enrichmentGHSA-cwph-f4w9-f4wq · GitHub severity HIGH · GitHub CVSS 7.1
  21. 2026-10-18 16:32 UTCEPSS rescoreEPSS 1.7% · 77th percentile
  22. 2026-10-18 08:34 UTCGHSA enrichmentGHSA-cwph-f4w9-f4wq · GitHub severity HIGH · GitHub CVSS 7.1
  23. 2026-10-18 03:21 UTCEG score recompute
  24. 2026-10-17 16:35 UTCEPSS rescoreEPSS 1.7% · 77th percentile
  25. 2026-10-17 08:15 UTCEG score recompute
  26. 2026-10-17 08:15 UTCGHSA enrichmentGHSA-cwph-f4w9-f4wq · GitHub severity HIGH · GitHub CVSS 7.1
  27. 2026-10-16 16:43 UTCEPSS rescoreEPSS 1.7% · 77th percentile
  28. 2026-10-16 07:56 UTCEG score recompute
  29. 2026-10-16 07:56 UTCGHSA enrichmentGHSA-cwph-f4w9-f4wq · GitHub severity HIGH · GitHub CVSS 7.1
  30. 2026-10-15 16:32 UTCEPSS rescoreEPSS 1.7% · 77th percentile
  31. 2026-10-15 07:34 UTCEG score recompute
  32. 2026-10-15 07:34 UTCGHSA enrichmentGHSA-cwph-f4w9-f4wq · GitHub severity HIGH · GitHub CVSS 7.1
  33. 2026-10-14 16:33 UTCEPSS rescoreEPSS 1.7% · 77th percentile
  34. 2026-10-14 07:14 UTCEG score recompute
  35. 2026-10-14 07:14 UTCGHSA enrichmentGHSA-cwph-f4w9-f4wq · GitHub severity HIGH · GitHub CVSS 7.1
  36. 2026-10-13 16:34 UTCEPSS rescoreEPSS 1.7% · 76th percentile
  37. 2026-10-13 06:54 UTCEG score recompute
  38. 2026-10-13 06:54 UTCGHSA enrichmentGHSA-cwph-f4w9-f4wq · GitHub severity HIGH · GitHub CVSS 7.1
  39. 2026-10-12 16:34 UTCEPSS rescoreEPSS 1.7% · 76th percentile
  40. 2026-10-12 15:47 UTCEG score recompute
  41. 2026-10-12 06:33 UTCGHSA enrichmentGHSA-cwph-f4w9-f4wq · GitHub severity HIGH · GitHub CVSS 7.1
  42. 2026-10-12 02:40 UTCGHSA enrichmentGHSA-cwph-f4w9-f4wq · GitHub severity HIGH · GitHub CVSS 7.1
  43. 2026-10-11 22:47 UTCGHSA enrichmentGHSA-cwph-f4w9-f4wq · GitHub severity HIGH · GitHub CVSS 7.1
  44. 2026-10-11 19:32 UTCEG score recompute
  45. 2026-10-11 18:54 UTCGHSA enrichmentGHSA-cwph-f4w9-f4wq · GitHub severity HIGH · GitHub CVSS 7.1
  46. 2026-10-11 16:47 UTCEG score recompute
  47. 2026-10-11 15:01 UTCGHSA enrichmentGHSA-cwph-f4w9-f4wq · GitHub severity HIGH · GitHub CVSS 7.1
  48. 2026-10-11 14:08 UTCEG score recompute
  49. 2026-10-11 13:49 UTCEPSS rescoreEPSS 1.7% · 76th percentile
  50. 2026-10-11 11:08 UTCGHSA enrichmentGHSA-cwph-f4w9-f4wq · GitHub severity HIGH · GitHub CVSS 7.1
  51. 2026-10-11 07:15 UTCGHSA enrichmentGHSA-cwph-f4w9-f4wq · GitHub severity HIGH · GitHub CVSS 7.1
  52. 2026-10-11 03:21 UTCGHSA enrichmentGHSA-cwph-f4w9-f4wq · GitHub severity HIGH · GitHub CVSS 7.1
  53. 2026-10-10 23:26 UTCEG score recompute
  54. 2026-10-10 23:26 UTCGHSA enrichmentGHSA-cwph-f4w9-f4wq · GitHub severity HIGH · GitHub CVSS 7.1
  55. 2026-10-10 20:00 UTCEPSS rescoreEPSS 1.7% · 76th percentile
  56. 2026-10-10 19:32 UTCGHSA enrichmentGHSA-cwph-f4w9-f4wq · GitHub severity HIGH · GitHub CVSS 7.1
  57. 2026-10-10 15:40 UTCGHSA enrichmentGHSA-cwph-f4w9-f4wq · GitHub severity HIGH · GitHub CVSS 7.1
  58. 2026-10-10 11:46 UTCGHSA enrichmentGHSA-cwph-f4w9-f4wq · GitHub severity HIGH · GitHub CVSS 7.1
  59. 2026-10-10 07:53 UTCGHSA enrichmentGHSA-cwph-f4w9-f4wq · GitHub severity HIGH · GitHub CVSS 7.1
  60. 2026-10-10 03:58 UTCGHSA enrichmentGHSA-cwph-f4w9-f4wq · GitHub severity HIGH · GitHub CVSS 7.1
  61. 2026-10-10 00:04 UTCGHSA enrichmentGHSA-cwph-f4w9-f4wq · GitHub severity HIGH · GitHub CVSS 7.1
  62. 2026-10-09 20:11 UTCEG score recompute
  63. 2026-10-09 20:11 UTCGHSA enrichmentGHSA-cwph-f4w9-f4wq · GitHub severity HIGH · GitHub CVSS 7.1
  64. 2026-10-09 20:07 UTCEPSS rescoreEPSS 1.7% · 76th percentile
  65. 2026-10-09 16:18 UTCGHSA enrichmentGHSA-cwph-f4w9-f4wq · GitHub severity HIGH · GitHub CVSS 7.1
  66. 2026-10-09 12:24 UTCGHSA enrichmentGHSA-cwph-f4w9-f4wq · GitHub severity HIGH · GitHub CVSS 7.1
  67. 2026-10-09 08:29 UTCGHSA enrichmentGHSA-cwph-f4w9-f4wq · GitHub severity HIGH · GitHub CVSS 7.1
  68. 2026-10-09 04:36 UTCGHSA enrichmentGHSA-cwph-f4w9-f4wq · GitHub severity HIGH · GitHub CVSS 7.1
  69. 2026-10-09 00:43 UTCGHSA enrichmentGHSA-cwph-f4w9-f4wq · GitHub severity HIGH · GitHub CVSS 7.1
  70. 2026-10-08 20:51 UTCEG score recompute
  71. 2026-10-08 20:50 UTCGHSA enrichmentGHSA-cwph-f4w9-f4wq · GitHub severity HIGH · GitHub CVSS 7.1
  72. 2026-10-08 17:13 UTCEPSS rescoreEPSS 1.7% · 76th percentile
  73. 2026-10-08 16:58 UTCGHSA enrichmentGHSA-cwph-f4w9-f4wq · GitHub severity HIGH · GitHub CVSS 7.1
  74. 2026-10-08 13:04 UTCGHSA enrichmentGHSA-cwph-f4w9-f4wq · GitHub severity HIGH · GitHub CVSS 7.1
  75. 2026-10-08 09:09 UTCGHSA enrichmentGHSA-cwph-f4w9-f4wq · GitHub severity HIGH · GitHub CVSS 7.1

Publicly available exploits

(3 references)

Public exploit code is referenced for this CVE (3 GitHub PoCs). Defenders should treat patch urgency accordingly.

  • GitHub PoCacheong08/CVE-2026-65400
    Published Aug 22, 2026

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

    Open source ↗
  • GitHub PoCpanchocosil/CVE-2026-65400-poc
    Published 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
    Published Aug 18, 2026

    CVE-2026-65400 - Draft or TODO

    Open source ↗

Frequently asked(6)

What is CVE-2026-65400?
CVE-2026-65400 is a critical-severity vulnerability; its CVE record was 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 the CVE record for CVE-2026-65400 published?
The CVE record for CVE-2026-65400 was published on August 6, 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 October 26, 2026; the record at its source may have been updated since.
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. The CVE record names the fixed release. 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?
The CVE record for CVE-2026-65400 names the fix: "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." 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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