CVE-2026-20665: This issue was addressed through improved state management
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This month
MEDIUM 6.5REMOTEUPGRADEUPGRADEUPGRADE
CVE-2026-20665 is a medium-severity flaw (CVSS 6.5) affecting safari, ipados, iphone os. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
This issue was addressed through improved state management. This issue is fixed in Safari 26.4, iOS 18.7.7 and iPadOS 18.7.7, iOS 26.4 and iPadOS 26.4, macOS Tahoe 26.4, tvOS 26.4, visionOS 26.4, watchOS 26.4. Processing maliciously crafted web content may prevent Content Security Policy from being enforced.
Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.
apple ipados UPGRADE
Affected: < 18.7.7 · >= 26.0 and < 26.4
Fixed in: 18.7.7, 26.4
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 iphone os UPGRADE
Affected: < 18.7.7 · >= 26.0 and < 26.4
Fixed in: 18.7.7, 26.4
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 macos UPGRADE
Affected: < 26.4
Fixed in: 26.4
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 tvos UPGRADE
Affected: < 26.4
Fixed in: 26.4
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 visionos UPGRADE
Affected: < 26.4
Fixed in: 26.4
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 sourceNVD · 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-2026-20665?
safari: upgrade to 26.4; ipados: upgrade to 18.7.7, 26.4; iphone os: upgrade to 18.7.7, 26.4. Exact commands for each OS are on this page.
Is CVE-2026-20665 being exploited?
CVE-2026-20665 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-2026-20665 affect?
CVE-2026-20665 affects safari, ipados, iphone os. Severity is medium (CVSS 6.5). This issue was addressed through improved state management. This issue is fixed in Safari 26.4, iOS 18.7.7 and iPadOS 18.7.7, iOS 26.4 and iPadOS 26.4, macOS Tahoe 26.4, tvOS 26.4, visionOS 26.4, watchOS 26.4. Processing maliciously crafted
How urgent is CVE-2026-20665?
Priority 40/100. Remotely exploitable, no login, no user action
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