Safari: Protection Mechanism Failure
CVE-2026-43660 is a high-severity protection mechanism failure vulnerability in Safari from Apple, with a CVSS 3.1 base score of 7.5 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. The record lists version 26.5 as the first without the flaw, so updating Safari to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.27% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Safari to 26.5 or a later version.
- Update iOS and iPadOS to 18.7.9 or 26.5, whichever matches your release line, or a later version.
- Update macOS to 26.5 or a later version.
- Read the advisory on support.apple.com for workarounds and exact fixed builds.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Apple | Safari | before 26.5 | 26.5 |
| Apple | iOS and iPadOS | before 18.7.9; before 26.5 | 18.7.9, 26.5 |
| Apple | macOS | before 26.5 | 26.5 |
| Apple | tvOS | before 26.5 | 26.5 |
| Apple | visionOS | before 26.5 | 26.5 |
| Apple | watchOS | before 26.5 | 26.5 |
| Apple | iPadOS | before 18.7.9; 26.0 up to, but not including, 26.5 | 18.7.9, 26.5 |
| Apple | Iphone OS | before 18.7.9; 26.0 up to, but not including, 26.5 | 18.7.9, 26.5 |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- NoneNothing can be modified.
- Availability
- NoneAvailability is not affected.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N. Scored by CISA (ADP).
Official description
A validation issue was addressed with improved logic. This issue is fixed in Safari 26.5, iOS 18.7.9 and iPadOS 18.7.9, iOS 26.5 and iPadOS 26.5, macOS Tahoe 26.5, tvOS 26.5, visionOS 26.5, watchOS 26.5. Processing maliciously crafted web content may prevent Content Security Policy from being enforced.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Protection Mechanism Failure
The product does not use or incorrectly uses a protection mechanism that provides sufficient defense against directed attacks against the product.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Advisories
- support.apple.com/en-us/127110Release Notes
- support.apple.com/en-us/127111Release Notes
- support.apple.com/en-us/127115Release Notes
- support.apple.com/en-us/127118Release Notes
- support.apple.com/en-us/127119Release Notes
- support.apple.com/en-us/127120Release Notes
Other references
Other vulnerabilities in Safari
- 7.5 High severity
- 7.5 High severity
- 8.8 High severity
- 10.0 Critical severity
- 8.8 High severity
- 8.8 High severity
Recent Protection Mechanism Failure vulnerabilities
- 8.1 High severity
- 8.1 High severity
- 8.3 High severity
- 7.8 High severity
- 9.8 Critical severity
- 8.1 High severity
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