Safari: Protection Mechanism Failure
CVE-2026-43670 is a high-severity protection mechanism failure vulnerability in Safari from Apple, with a CVSS 3.1 base score of 8.8 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, but only if a user takes part, for example by opening a link or file. 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 0.22% 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.
- Because the attack needs a user to take part, warn users about unexpected links and files related to this product until it is patched.
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 | 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
- RequiredA user must take an action such as opening a file or link.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H. Scored by CISA (ADP).
Official description
A Content Security Policy bypass was addressed with improved enforcement in AudioWorklet contexts. 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. Processing maliciously crafted web content may bypass Content Security Policy.
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: no, 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/127121Release Notes
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
- 8.4 High severity
- 10.0 Critical severity
- 8.1 High severity
- 9.1 Critical severity
- 8.1 High severity
- 9.1 Critical severity
Spotted an error? Tell us.