dbcve.org
SafariWeb browser · Apple

CVE-2026-20665

MEDIUM · 6.5 CVSS v3.1 Published 2026-03-25
Fix available
A fix is available. Upgrade to 18.7.7 / 26.4 or later.
See remediation →
74/100
Remediation priority · Elevated
Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
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.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · moderate confidence

This is a Content Security Policy (CSP) bypass vulnerability in Apple's WebKit browser engine. Maliciously crafted web content can prevent CSP from being enforced due to improper state management, allowing attackers to potentially bypass security controls designed to prevent XSS and data injection attacks.

MitigationApply the vendor-supplied updates: Safari 26.4, iOS 18.7.7/iPadOS 18.7.7, and the 26.4 versions of iOS, iPadOS, macOS Tahoe, tvOS, visionOS, and watchOS.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
SafariWeb browser
Affected:< 26.4
IpadosOperating system
Affected:< 18.7.7>= 26.0, < 26.4
Iphone OsOperating system
Affected:< 18.7.7>= 26.0, < 26.4
macOSOperating system
Affected:< 26.4
TvosOperating system
Affected:< 26.4
VisionosOperating system
Affected:< 26.4
WatchosOperating system
Affected:< 26.4

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
Low
Integrity
None
Availability
Low

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:L

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Check Safari version on macOS
    Open Safari, go to Safari menu > About Safari, note the version number displayed
    Affected if Version is less than 26.4
  2. Check iOS version on iPhone
    Open Settings app > General > About, note the iOS version number
    Affected if Version is less than 18.7.7 OR version is 26.0 through 26.3
  3. Check iPadOS version on iPad
    Open Settings app > General > About, note the iPadOS version number
    Affected if Version is less than 18.7.7 OR version is 26.0 through 26.3
  4. Check macOS version
    Open System Settings (or System Preferences on older versions) > General > About, note the macOS version
    Affected if Version corresponds to a macOS release older than 26.4 (Apple typically lists macOS versions by name like Tahoe, Sonoma, etc.)
  5. Check tvOS version on Apple TV
    Open Settings app > General > About, note the tvOS version number
    Affected if Version is less than 26.4
  6. Check visionOS version on Apple Vision Pro
    Open Settings app > General > About, note the visionOS version number
    Affected if Version is less than 26.4

You are affected if any Apple device you use runs Safari or a WebKit-based browser with a version lower than the fixed releases (26.4 for most products, 18.7.7 for iOS/iPadOS) and you browse the web where malicious content could be encountered.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 18.7.7 / 26.4 or later
Fixed in 18.7.726.4
Interim mitigation

Apply the vendor-supplied updates: Safari 26.4, iOS 18.7.7/iPadOS 18.7.7, and the 26.4 versions of iOS, iPadOS, macOS Tahoe, tvOS, visionOS, and watchOS.

Recommended fix High confidence

Upgrade to Safari 26.4, iOS 18.7.7 or 26.4 (per current version), iPadOS 18.7.7 or 26.4 (per current version), macOS Tahoe 26.4, tvOS 26.4, visionOS 26.4, or watchOS 26.4

  1. For Safari users: Update to Safari 26.4
  2. For iOS users: If currently on a version < 18.7.7, upgrade to iOS 18.7.7; If currently on version >= 26.0 but < 26.4, upgrade to iOS 26.4
  3. For iPadOS users: If currently on a version < 18.7.7, upgrade to iPadOS 18.7.7; If currently on version >= 26.0 but < 26.4, upgrade to iPadOS 26.4
  4. For macOS users: Update to macOS Tahoe 26.4
  5. For tvOS users: Update to tvOS 26.4
  6. For visionOS users: Update to visionOS 26.4
  7. For watchOS users: Update to watchOS 26.4
  8. After updating, verify Content Security Policy is properly enforced on affected web content

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Safari Scoped from the published advisory
  • Consultation2.0 h
  • Implementation1.0 h
  • Testing2.0 h
  • Review / QA1.0 h
6.0 hours of engineering $1,060
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,696.

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-20665 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data