CVE-2026-39877: A memory corruption issue was addressed with improved memory handling

Q: How do I fix CVE-2026-39877?

macos: upgrade to 14.8.8, 15.7.8. Exact commands for each OS are on this page.

Q: Is CVE-2026-39877 being exploited?

CVE-2026-39877 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2026-39877 affect?

CVE-2026-39877 affects macos. Severity is high (CVSS 7.8). 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, w

Routine

HIGH 7.8UPGRADE

CVE-2026-39877 is a high-severity flaw (CVSS 7.8) affecting macos. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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.

Why this priority

High severity

A fixed release or distro patch exists.

Risk facts

CVSS score	7.8 (High)
Attack vector	Local
Attack complexity	Low
Privileges needed	None
User interaction	Required
EPSS exploit chance	0.2% (top 94%)
CISA exploited list	No
Weakness	CWE-119
Published	2026-07-27
Last modified	2026-10-24

Publisher (CNA): Apple Inc. · Vendor: apple

Last updated 2026-10-24 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-07-27 21:16 UTCPublished CVE record published
2026-10-24 13:10 UTCUpdated Record last modified

apple macos UPGRADE

Affected: >= 14.0 and < 14.8.8 · >= 15.0 and < 15.7.8

Fixed in: 14.8.8, 15.7.8

Safe to downgrade to: a release before 14.0

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-39877?

macos: upgrade to 14.8.8, 15.7.8. Exact commands for each OS are on this page.

Is CVE-2026-39877 being exploited?

CVE-2026-39877 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-39877 affect?

CVE-2026-39877 affects macos. Severity is high (CVSS 7.8). 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, w

How urgent is CVE-2026-39877?

Priority 29/100. High severity

Software pages

iOS vulnerabilities · macOS vulnerabilities · iPadOS vulnerabilities · watchOS vulnerabilities · tvOS vulnerabilities

Related CVEs

CVE-2026-65400 CRITICAL 9.8 EXPLOITED UPGRADE Apple macOS Improper Authentication Vulnerability
CVE-2026-43715 HIGH 8.8 UPGRADE UPGRADE A use-after-free issue was addressed with improved memory management
CVE-2026-43682 CRITICAL 9.8 UPGRADE The issue was addressed with improved memory handling
CVE-2026-64695 CRITICAL 9.8 UPGRADE The issue was addressed with improved memory handling
CVE-2026-64696 CRITICAL 9.8 UPGRADE The issue was addressed with improved memory handling

References

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