CVE-2026-84521: A use after free issue was addressed with improved memory management

Q: How do I fix CVE-2026-84521?

ipados: upgrade to 26.7; iphone os: upgrade to 26.7; macos: upgrade to 15.8, 26.7. Exact commands for each OS are on this page.

Q: Is CVE-2026-84521 being exploited?

CVE-2026-84521 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-2026-84521 affect?

CVE-2026-84521 affects ipados, iphone os, macos. Severity is medium (CVSS 5.5). A use after free issue was addressed with improved memory management. This issue is fixed in iOS 26.7 and iPadOS 26.7, iOS 27 and iPadOS 27, macOS Golden Gate 27, macOS Sequoia 15.8, macOS Tahoe 26.7, visionOS 27. An app may be able to caus

Q: How urgent is CVE-2026-84521?

Priority 20/100. No elevated risk signals yet.

Routine

MEDIUM 5.5UPGRADEUPGRADEUPGRADE

CVE-2026-84521 is a medium-severity flaw (CVSS 5.5) affecting ipados, iphone os, macos. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

A use after free issue was addressed with improved memory management. This issue is fixed in iOS 26.7 and iPadOS 26.7, iOS 27 and iPadOS 27, macOS Golden Gate 27, macOS Sequoia 15.8, macOS Tahoe 26.7, visionOS 27. An app may be able to cause unexpected system termination.

Why this priority

No elevated risk signals yet

A fixed release or distro patch exists.

Risk facts

CVSS score	5.5 (Medium)
Attack vector	Local
Attack complexity	Low
Privileges needed	Low
User interaction	None
EPSS exploit chance	0.2% (top 96%)
CISA exploited list	No
Weakness	CWE-416
Published	2026-09-14
Last modified	2026-09-16

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

Last updated 2026-09-16 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-09-14 21:17 UTCPublished CVE record published
2026-09-16 01:07 UTCUpdated Record last modified

apple ipados UPGRADE

Affected: < 26.7

Fixed in: 26.7

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.

apple iphone os UPGRADE

Affected: < 26.7

Fixed in: 26.7

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.

apple macos UPGRADE

Affected: >= 15.0 and < 15.8 · >= 26.0 and < 26.7

Fixed in: 15.8, 26.7

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: < 27.0

Fixed in: 27.0

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.

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-2026-84521?

ipados: upgrade to 26.7; iphone os: upgrade to 26.7; macos: upgrade to 15.8, 26.7. Exact commands for each OS are on this page.

Is CVE-2026-84521 being exploited?

CVE-2026-84521 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-2026-84521 affect?

CVE-2026-84521 affects ipados, iphone os, macos. Severity is medium (CVSS 5.5). A use after free issue was addressed with improved memory management. This issue is fixed in iOS 26.7 and iPadOS 26.7, iOS 27 and iPadOS 27, macOS Golden Gate 27, macOS Sequoia 15.8, macOS Tahoe 26.7, visionOS 27. An app may be able to caus

How urgent is CVE-2026-84521?

Priority 20/100. No elevated risk signals yet.

Software pages

iOS vulnerabilities · macOS vulnerabilities · iPadOS vulnerabilities

Related CVEs

CVE-2026-28950 MEDIUM 6.2 UPGRADE UPGRADE A logging issue was addressed with improved data redaction
CVE-2026-43661 HIGH 7.5 UPGRADE UPGRADE A buffer overflow issue was addressed with improved memory handling
CVE-2026-28972 MEDIUM 6.5 UPGRADE UPGRADE An out-of-bounds write issue was addressed with improved input validation
CVE-2026-28846 HIGH 7.5 UPGRADE UPGRADE A buffer overflow was addressed with improved bounds checking
CVE-2026-28952 HIGH 7.5 UPGRADE UPGRADE An integer overflow was addressed with improved input validation

References

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