CVE-2026-28931: A buffer overflow was addressed with improved bounds checking

Q: How do I fix CVE-2026-28931?

ipados: upgrade to 26.6; iphone os: upgrade to 26.6; macos: upgrade to 26.6. Exact commands for each OS are on this page.

Q: Is CVE-2026-28931 being exploited?

CVE-2026-28931 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-2026-28931 affect?

CVE-2026-28931 affects ipados, iphone os, macos. Severity is high (CVSS 8.8). A buffer overflow was addressed with improved bounds checking. This issue is fixed in iOS 26.6 and iPadOS 26.6, macOS Tahoe 26.6, tvOS 26.6, watchOS 26.6. Connecting to a malicious NFS server may lead to kernel memory corruption.

This month

HIGH 8.8UPGRADEUPGRADEUPGRADE

CVE-2026-28931 is a high-severity flaw (CVSS 8.8) 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 26.6 and iPadOS 26.6, macOS Tahoe 26.6, tvOS 26.6, watchOS 26.6. Connecting to a malicious NFS server may lead to kernel memory corruption.

Why this priority

High severity

A fixed release or distro patch exists.

Risk facts

CVSS score	8.8 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	Required
EPSS exploit chance	0.5% (top 58%)
CISA exploited list	No
Weakness	CWE-120
Published	2026-07-27
Last modified	2026-07-29

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

Last updated 2026-07-29 · 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
2026-07-29 05:16 UTCUpdated Record last modified

apple ipados UPGRADE

Affected: < 26.6

Fixed in: 26.6

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: < 26.6

Fixed in: 26.6

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: >= 26.0 and < 26.6

Fixed in: 26.6

Safe to downgrade to: a release before 26.0

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 tvos UPGRADE

Affected: < 26.6

Fixed in: 26.6

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 watchos UPGRADE

Affected: < 26.6

Fixed in: 26.6

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-2026-28931?

ipados: upgrade to 26.6; iphone os: upgrade to 26.6; macos: upgrade to 26.6. Exact commands for each OS are on this page.

Is CVE-2026-28931 being exploited?

CVE-2026-28931 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-2026-28931 affect?

CVE-2026-28931 affects ipados, iphone os, macos. Severity is high (CVSS 8.8). A buffer overflow was addressed with improved bounds checking. This issue is fixed in iOS 26.6 and iPadOS 26.6, macOS Tahoe 26.6, tvOS 26.6, watchOS 26.6. Connecting to a malicious NFS server may lead to kernel memory corruption.

How urgent is CVE-2026-28931?

Priority 41/100. High severity

Software pages

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

Related CVEs

CVE-2026-86950 HIGH 8.8 EXPLOITED UPGRADE UPGRADE Apple Multiple Products Out-of-Bounds Write Vulnerability
CVE-2026-65339 MEDIUM 5.0 UPGRADE UPGRADE A logic issue was addressed with improved checks
CVE-2026-28991 HIGH 7.5 UPGRADE UPGRADE An out-of-bounds read was addressed with improved bounds checking
CVE-2026-28864 LOW 3.3 UPGRADE UPGRADE This issue was addressed with improved permissions checking
CVE-2026-20649 HIGH 7.5 UPGRADE UPGRADE A logging issue was addressed with improved data redaction

References

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