CVE-2026-86991: A buffer overflow was addressed with improved bounds checking

Q: How do I fix CVE-2026-86991?

ipados: upgrade to 26.7.2, 27.2; iphone os: upgrade to 26.7.2, 27.2; macos: upgrade to 15.8.2, 26.7.2, 27.2. Exact commands for each OS are on this page.

Q: Is CVE-2026-86991 being exploited?

CVE-2026-86991 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-2026-86991 affect?

CVE-2026-86991 affects ipados, iphone os, macos. Severity is high (CVSS 7.5). A buffer overflow was addressed with improved bounds checking. This issue is fixed in iOS 26.7.2 and iPadOS 26.7.2, iOS 27.2 and iPadOS 27.2, macOS Golden Gate 27.2, macOS Sequoia 15.8.2, macOS Tahoe 26.7.2, visionOS 27.2. Processing a mali

Q: How urgent is CVE-2026-86991?

Priority 45/100. High severity; Remotely exploitable, no login, no user action

This month

HIGH 7.5REMOTEUPGRADEUPGRADEUPGRADE

CVE-2026-86991 is a high-severity flaw (CVSS 7.5) affecting ipados, iphone os, macos. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

A buffer overflow was addressed with improved bounds checking. This issue is fixed in iOS 26.7.2 and iPadOS 26.7.2, iOS 27.2 and iPadOS 27.2, macOS Golden Gate 27.2, macOS Sequoia 15.8.2, macOS Tahoe 26.7.2, visionOS 27.2. Processing a maliciously crafted file may lead to unexpected process termination.

Why this priority

High severity
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	7.5 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.8% (top 44%)
CISA exploited list	No
Weakness	CWE-120
Published	2026-10-26
Last modified	2026-11-04

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

Last updated 2026-11-04 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-10-26 21:20 UTCPublished CVE record published
2026-11-04 17:04 UTCUpdated Record last modified

apple ipados UPGRADE

Affected: < 26.7.2 · >= 27.0 and < 27.2

Fixed in: 26.7.2, 27.2

Safe to downgrade to: a release before 27.0

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.

apple iphone os UPGRADE

Affected: < 26.7.2 · >= 27.0 and < 27.2

Fixed in: 26.7.2, 27.2

Safe to downgrade to: a release before 27.0

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.

apple macos UPGRADE

Affected: >= 15.0 and < 15.8.2 · >= 26.0 and < 26.7.2 · >= 27.0 and < 27.2

Fixed in: 15.8.2, 26.7.2, 27.2

Safe to downgrade to: a release before 15.0

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.

apple visionos UPGRADE

Affected: < 27.2

Fixed in: 27.2

Safe to downgrade to: no unaffected older release

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.

Advisories and coverage

Research and news

Vulners Bulletins: CVE-2026-86991 2026-10-26

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-2026-86991?

ipados: upgrade to 26.7.2, 27.2; iphone os: upgrade to 26.7.2, 27.2; macos: upgrade to 15.8.2, 26.7.2, 27.2. Exact commands for each OS are on this page.

Is CVE-2026-86991 being exploited?

CVE-2026-86991 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-2026-86991 affect?

CVE-2026-86991 affects ipados, iphone os, macos. Severity is high (CVSS 7.5). A buffer overflow was addressed with improved bounds checking. This issue is fixed in iOS 26.7.2 and iPadOS 26.7.2, iOS 27.2 and iPadOS 27.2, macOS Golden Gate 27.2, macOS Sequoia 15.8.2, macOS Tahoe 26.7.2, visionOS 27.2. Processing a mali

How urgent is CVE-2026-86991?

Priority 45/100. High severity; Remotely exploitable, no login, no user action

Software pages

iOS vulnerabilities · macOS vulnerabilities · iPadOS vulnerabilities

Related CVEs

CVE-2024-27834 MEDIUM 5.5 UPGRADE UPGRADE The issue was addressed with improved checks
CVE-2026-112571 MEDIUM 5.5 UPGRADE UPGRADE A memory initialization issue was addressed with improved memory handling
CVE-2026-112576 MEDIUM 6.5 UPGRADE UPGRADE A memory integrity issue was addressed with improved handling of copy-on-write pages
CVE-2026-112595 HIGH 7.5 UPGRADE UPGRADE This issue was addressed with improved authentication
CVE-2026-86969 HIGH 7.5 UPGRADE UPGRADE An out-of-bounds write was addressed with improved input validation

References

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