Apple Multiple Products Use-After-Free WebKit
CVE-2025-43529 is a high-severity use after free 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 26.2 as the first without the flaw, so updating Safari to that release or later removes the exposure. CISA added it to the Known Exploited Vulnerabilities catalogue on December 15, 2025, which means attacks have been observed in the wild.
Attackers are already exploiting this vulnerability, according to CISA.
What to do
- Update Safari to 26.2 or a later version.
- Update iOS and iPadOS to 18.7.3 or 26.2, whichever matches your release line, or a later version.
- Update macOS to 26.2 or a later version.
- CISA's required action: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
- 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 26.2 | 26.2 |
| Apple | iOS and iPadOS | before 18.7.3; before 26.2 | 18.7.3, 26.2 |
| Apple | macOS | before 26.2 | 26.2 |
| Apple | tvOS | before 26.2 | 26.2 |
| Apple | visionOS | before 26.2 | 26.2 |
| Apple | watchOS | before 26.2 | 26.2 |
| Apple | iPadOS | before 18.7.3; 26.0 up to, but not including, 26.2 | 18.7.3, 26.2 |
| Apple | Iphone OS | before 18.7.3; 26.0 up to, but not including, 26.2 | 18.7.3, 26.2 |
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 use-after-free issue was addressed with improved memory management. This issue is fixed in Safari 26.2, iOS 18.7.3 and iPadOS 18.7.3, iOS 26.2 and iPadOS 26.2, macOS Tahoe 26.2, tvOS 26.2, visionOS 26.2, watchOS 26.2. Processing maliciously crafted web content may lead to arbitrary code execution. Apple is aware of a report that this issue may have been exploited in an extremely sophisticated attack against specific targeted individuals on versions of iOS before iOS 26. CVE-2025-14174 was also issued in response to this report.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Use After Free
The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory belongs to the code that operates on the new pointer.
How developers prevent this class of flaw
- Choose a language that provides automatic memory management.
- When freeing pointers, be sure to set them to NULL once they are freed. However, the utilization of multiple or complex data structures may lower the usefulness of this strategy.
Timeline
- Added to CISA's Known Exploited Vulnerabilities catalogue.
- CVE record published.
- CISA published its SSVC assessment (exploitation: active, automatable: no, technical impact: total).
- Deadline for US federal agencies to remediate, set by CISA.
- Record last changed materially (score, affected products, status or references).
References
Advisories
- support.apple.com/en-us/125884Release Notes
- support.apple.com/en-us/125885Release Notes
- support.apple.com/en-us/125886Release Notes
- support.apple.com/en-us/125889Release Notes
- support.apple.com/en-us/125890Release Notes
- support.apple.com/en-us/125891Release Notes
- support.apple.com/en-us/125892Release Notes
Third-party and government advisories
- cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-43529US Government Resource
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 Use After Free vulnerabilities
- 8.8 High severity
- 8.8 High severity
- 7.8 High severity
- 7.8 High severity
Microsoft Windows Use After Free Exploited
- 7.8 High severity
- 9.8 Critical severity
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