CVE-2026-39877

HIGHPre-NVD 7.87.8
EchelonGraph scoreMEDIUM confidence

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

Score 7.8 from GitHub Security Advisory (severity: HIGH) published 2026-07-27. CISA-ADP (Vulnrichment) CVSS v3.1 baseline 7.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: CISA-ADP (Vulnrichment) CVSS v3.1, EPSS, GitHub Security Advisory
7.8EG
EchelonGraph verdictPlan a fixRemediate within your standard update timelines (the SSVC decision on this page).
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0.2%CVSS: 7.8Exploit: None knownExposed services: Not assessed

The CVE record names the fixed release — apply it.

A memory corruption issue was addressed with improved memory handling. This issue is fixed in iOS 18.7.10 and iPadOS 18.7.10, iOS 26.5 and iPadOS 26.5, macOS Sequoia 15.7.8, macOS Sonoma 14.8.8, macOS Tahoe 26.5, tvOS 26.5, visionOS 26.5, watchOS 26.5. An app may be able to disclose kernel memory.

CVSS v3
7.8
EG Score
7.8HIGHmedium confidence
EG Risk
35
EG Risk 35/100

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 (value × EchelonGraph’s weight)
Severity78% × 45%
The EG Score, 7.8 of 10.
Exploitation0.2% × 40%
FIRST EPSS: the 30-day exploitation probability when EchelonGraph scored this CVE.
Automatability0% × 15%
CISA's SSVC Automatable value: no (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at low or medium mission impact; Track* at high (mission-essential systems).
Exploitation none (CISA Vulnrichment) · Automatable no (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 within your standard update timelines.
EPSS PROB
0.2%
EPSS %ILE
6th
KEV
Not listed

SSVC (CISA's decision table, applied by EchelonGraph)Track at low or medium mission impact; Track* at high (mission-essential systems).

The CVE record names the fixed release. Apply it within your standard update timelines.

Exploitation none (CISA Vulnrichment) · Automatable no (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)14 days if the affected system is publicly exposed; Fix on system upgrade if it is not.

In CISA KEV no (CISA's KEV catalog) · Automatable no (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

Published

July 27, 2026

Last Modified

August 25, 2026

Advisory Details (2)

Auto-updated Jul 28, 2026
Fix named in the CVE record.
Web page

About the security content of macOS Sonoma 14.8.8 - Apple Support

https://support.apple.com/en-us/128072
Web page

About the security content of macOS Sequoia 15.7.8 - Apple Support

https://support.apple.com/en-us/128071

Vendor Advisories for CVE-2026-39877(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 11× in last 7d / 62× 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 98 of 240 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. 2 repeat rows among the latest 100 are merged into the row they repeat. The 142 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-10-13 16:34 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  2. 2026-10-12 16:34 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  3. 2026-10-12 16:10 UTCEG score recompute
  4. 2026-10-11 19:52 UTCEG score recompute
  5. 2026-10-11 17:05 UTCEG score recompute
  6. 2026-10-11 14:32 UTCEG score recompute
  7. 2026-10-11 13:48 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  8. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  9. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  10. 2026-10-08 17:12 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  11. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  12. 2026-10-07 00:12 UTCEG score recompute
  13. 2026-10-07 00:12 UTCGHSA enrichmentGHSA-hvwx-8xwj-pgx8 · GitHub severity HIGH · GitHub CVSS 7.8
  14. 2026-10-06 15:17 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  15. 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  16. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  17. 2026-10-04 07:15 UTCEG score recompute
  18. 2026-10-04 07:15 UTCGHSA enrichmentGHSA-hvwx-8xwj-pgx8 · GitHub severity HIGH · GitHub CVSS 7.8
  19. 2026-10-03 14:25 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  20. 2026-10-02 18:26 UTCEG score recompute
  21. 2026-10-02 18:26 UTCGHSA enrichmentGHSA-hvwx-8xwj-pgx8 · GitHub severity HIGH · GitHub CVSS 7.8
  22. 2026-10-01 19:49 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  23. 2026-10-01 15:15 UTCGHSA enrichmentGHSA-hvwx-8xwj-pgx8 · GitHub severity HIGH · GitHub CVSS 7.8
  24. 2026-10-01 03:49 UTCEG score recompute
  25. 2026-10-01 03:49 UTCGHSA enrichmentGHSA-hvwx-8xwj-pgx8 · GitHub severity HIGH · GitHub CVSS 7.8
Show 73 more
  1. 2026-09-30 15:03 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  2. 2026-09-29 07:50 UTCEG score recompute
  3. 2026-09-29 07:50 UTCGHSA enrichmentGHSA-hvwx-8xwj-pgx8 · GitHub severity HIGH · GitHub CVSS 7.8
  4. 2026-09-28 13:51 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  5. 2026-09-28 03:30 UTCEG score recompute
  6. 2026-09-28 03:30 UTCGHSA enrichmentGHSA-hvwx-8xwj-pgx8 · GitHub severity HIGH · GitHub CVSS 7.8
  7. 2026-09-27 13:48 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  8. 2026-09-26 15:58 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  9. 2026-09-26 00:26 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  10. 2026-09-25 06:42 UTCEG score recompute
  11. 2026-09-25 06:42 UTCGHSA enrichmentGHSA-hvwx-8xwj-pgx8 · GitHub severity HIGH · GitHub CVSS 7.8
  12. 2026-09-24 09:40 UTCGHSA enrichmentGHSA-hvwx-8xwj-pgx8 · GitHub severity HIGH · GitHub CVSS 7.8
  13. 2026-09-23 22:00 UTCEG score recompute
  14. 2026-09-23 22:00 UTCGHSA enrichmentGHSA-hvwx-8xwj-pgx8 · GitHub severity HIGH · GitHub CVSS 7.8
  15. 2026-09-23 09:10 UTCGHSA enrichmentGHSA-hvwx-8xwj-pgx8 · GitHub severity HIGH · GitHub CVSS 7.8
  16. 2026-09-22 21:46 UTCEG score recompute
  17. 2026-09-22 21:46 UTCGHSA enrichmentGHSA-hvwx-8xwj-pgx8 · GitHub severity HIGH · GitHub CVSS 7.8
  18. 2026-09-20 20:15 UTCEPSS rescoreEPSS 0.2% · 9th percentile
  19. 2026-09-20 00:45 UTCEG score recompute
  20. 2026-09-20 00:45 UTCGHSA enrichmentGHSA-hvwx-8xwj-pgx8 · GitHub severity HIGH · GitHub CVSS 7.8
  21. 2026-09-19 08:10 UTCEG score recompute
  22. 2026-09-19 08:10 UTCGHSA enrichmentGHSA-hvwx-8xwj-pgx8 · GitHub severity HIGH · GitHub CVSS 7.8
  23. 2026-09-18 19:28 UTCEPSS rescoreEPSS 0.2% · 9th percentile
  24. 2026-09-18 18:25 UTCGHSA enrichmentGHSA-hvwx-8xwj-pgx8 · GitHub severity HIGH · GitHub CVSS 7.8
  25. 2026-09-18 02:13 UTCEG score recompute
  26. 2026-09-18 02:13 UTCGHSA enrichmentGHSA-hvwx-8xwj-pgx8 · GitHub severity HIGH · GitHub CVSS 7.8
  27. 2026-09-17 19:30 UTCEPSS rescoreEPSS 0.2% · 9th percentile
  28. 2026-09-17 01:45 UTCEG score recompute
  29. 2026-09-17 01:45 UTCGHSA enrichmentGHSA-hvwx-8xwj-pgx8 · GitHub severity HIGH · GitHub CVSS 7.8
  30. 2026-09-16 14:08 UTCEPSS rescoreEPSS 0.2% · 9th percentile
  31. 2026-09-16 05:59 UTCEG score recompute
  32. 2026-09-16 05:59 UTCGHSA enrichmentGHSA-hvwx-8xwj-pgx8 · GitHub severity HIGH · GitHub CVSS 7.8
  33. 2026-09-16 05:15 UTCEPSS rescoreEPSS 0.2% · 9th percentile
  34. 2026-09-15 09:00 UTCEG score recompute
  35. 2026-09-15 09:00 UTCGHSA enrichmentGHSA-hvwx-8xwj-pgx8 · GitHub severity HIGH · GitHub CVSS 7.8
  36. 2026-09-15 03:11 UTCEPSS rescoreEPSS 0.2% · 9th percentile
  37. 2026-09-14 16:04 UTCGHSA enrichmentGHSA-hvwx-8xwj-pgx8 · GitHub severity HIGH · GitHub CVSS 7.8
  38. 2026-09-14 04:40 UTCGHSA enrichmentGHSA-hvwx-8xwj-pgx8 · GitHub severity HIGH · GitHub CVSS 7.8
  39. 2026-09-13 17:16 UTCEG score recompute
  40. 2026-09-13 17:16 UTCGHSA enrichmentGHSA-hvwx-8xwj-pgx8 · GitHub severity HIGH · GitHub CVSS 7.8
  41. 2026-09-13 16:47 UTCEPSS rescoreEPSS 0.2% · 9th percentile
  42. 2026-09-13 05:47 UTCGHSA enrichmentGHSA-hvwx-8xwj-pgx8 · GitHub severity HIGH · GitHub CVSS 7.8
  43. 2026-09-12 18:23 UTCEG score recompute
  44. 2026-09-12 18:23 UTCGHSA enrichmentGHSA-hvwx-8xwj-pgx8 · GitHub severity HIGH · GitHub CVSS 7.8
  45. 2026-09-12 15:01 UTCEPSS rescoreEPSS 0.2% · 9th percentile
  46. 2026-09-12 06:58 UTCGHSA enrichmentGHSA-hvwx-8xwj-pgx8 · GitHub severity HIGH · GitHub CVSS 7.8
  47. 2026-09-11 19:32 UTCEG score recompute
  48. 2026-09-11 19:32 UTCGHSA enrichmentGHSA-hvwx-8xwj-pgx8 · GitHub severity HIGH · GitHub CVSS 7.8
  49. 2026-09-11 14:53 UTCEPSS rescoreEPSS 0.2% · 9th percentile
  50. 2026-09-11 09:37 UTCEPSS rescoreEPSS 0.2% · 9th percentile
  51. 2026-09-11 08:07 UTCGHSA enrichmentGHSA-hvwx-8xwj-pgx8 · GitHub severity HIGH · GitHub CVSS 7.8
  52. 2026-09-10 20:42 UTCEG score recompute
  53. 2026-09-10 20:42 UTCGHSA enrichmentGHSA-hvwx-8xwj-pgx8 · GitHub severity HIGH · GitHub CVSS 7.8
  54. 2026-09-10 09:34 UTCEPSS rescoreEPSS 0.2% · 9th percentile
  55. 2026-09-10 08:01 UTCGHSA enrichmentGHSA-hvwx-8xwj-pgx8 · GitHub severity HIGH · GitHub CVSS 7.8
  56. 2026-09-09 08:14 UTCEG score recompute
  57. 2026-09-09 08:14 UTCGHSA enrichmentGHSA-hvwx-8xwj-pgx8 · GitHub severity HIGH · GitHub CVSS 7.8
  58. 2026-09-08 22:00 UTCEPSS rescoreEPSS 0.2% · 9th percentile
  59. 2026-09-07 20:59 UTCEG score recompute
  60. 2026-09-07 20:59 UTCGHSA enrichmentGHSA-hvwx-8xwj-pgx8 · GitHub severity HIGH · GitHub CVSS 7.8
  61. 2026-09-07 16:01 UTCEPSS rescoreEPSS 0.2% · 9th percentile
  62. 2026-09-06 18:45 UTCEG score recompute
  63. 2026-09-06 18:45 UTCGHSA enrichmentGHSA-hvwx-8xwj-pgx8 · GitHub severity HIGH · GitHub CVSS 7.8
  64. 2026-09-06 13:47 UTCEPSS rescoreEPSS 0.2% · 9th percentile
  65. 2026-09-06 07:20 UTCGHSA enrichmentGHSA-hvwx-8xwj-pgx8 · GitHub severity HIGH · GitHub CVSS 7.8
  66. 2026-09-05 19:13 UTCEG score recompute
  67. 2026-09-05 19:13 UTCGHSA enrichmentGHSA-hvwx-8xwj-pgx8 · GitHub severity HIGH · GitHub CVSS 7.8
  68. 2026-09-05 05:40 UTCEG score recompute
  69. 2026-09-05 05:40 UTCGHSA enrichmentGHSA-hvwx-8xwj-pgx8 · GitHub severity HIGH · GitHub CVSS 7.8
  70. 2026-09-04 12:16 UTCEG score recompute
  71. 2026-09-04 12:16 UTCGHSA enrichmentGHSA-hvwx-8xwj-pgx8 · GitHub severity HIGH · GitHub CVSS 7.8
  72. 2026-09-04 05:06 UTCEPSS rescoreEPSS 0.2% · 9th percentile
  73. 2026-09-02 14:12 UTCEPSS rescoreEPSS 0.2% · 9th percentile

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-39877?
CVE-2026-39877 is a high-severity vulnerability; its CVE record was published on July 27, 2026. A memory corruption issue was addressed with improved memory handling. This issue is fixed in iOS 18.7.10 and iPadOS 18.7.10, iOS 26.5 and iPadOS 26.5, macOS Sequoia 15.7.8, macOS Sonoma 14.8.8, macOS Tahoe 26.5, tvOS 26.5, visionOS 26.5, watchOS 26.5. An app may be able to disclose kernel memory.
When was the CVE record for CVE-2026-39877 published?
The CVE record for CVE-2026-39877 was published on July 27, 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 August 25, 2026; the record at its source may have been updated since.
Is CVE-2026-39877 actively exploited?
CVE-2026-39877 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.2% probability of exploitation in the next 30 days (6th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-39877?
CVE-2026-39877 has a CVSS v3.1 base score of 7.8 (CISA-ADP / Vulnrichment enrichment; NVD's own analysis pending).
How do I remediate CVE-2026-39877?
The CVE record for CVE-2026-39877 names the fix: "This issue is fixed in iOS 18.7.10 and iPadOS 18.7.10, iOS 26.5 and iPadOS 26.5, macOS Sequoia 15.7.8, macOS Sonoma 14.8.8, macOS Tahoe 26.5, tvOS 26.5, visionOS 26.5, watchOS 26.5." The vendor advisories EchelonGraph has for CVE-2026-39877 are linked in the Vendor Advisories panel on this page.

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