CyberSecBulletin
CVE-2026-43731NVD status: Modified

Safari: Use After Free

Published Updated By the CyberSecBulletin desk

CVE-2026-43731 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 26.5.2 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 0.4% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update Safari to 26.5.2 or a later version.
  2. Update iOS and iPadOS to 18.7.10 or 26.5.2, whichever matches your release line, or a later version.
  3. Update macOS to 26.5.2 or a later version.
  4. Read the advisory on support.apple.com for workarounds and exact fixed builds.
  5. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
  6. 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

VendorProductAffected versionsFixed in
AppleSafaribefore 26.5.226.5.2
AppleiOS and iPadOSbefore 18.7.10; before 26.5.218.7.10, 26.5.2
ApplemacOSbefore 26.5.226.5.2
AppletvOSbefore 26.626.6
ApplevisionOSbefore 26.626.6
ApplewatchOSbefore 26.626.6
AppleiPadOSbefore 26.5.226.5.2
AppleIphone OSbefore 26.5.226.5.2

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 26.5.2, iOS 18.7.10 and iPadOS 18.7.10, iOS 26.5.2 and iPadOS 26.5.2, macOS Tahoe 26.5.2, tvOS 26.6, visionOS 26.6, watchOS 26.6. Processing maliciously crafted web content may lead to memory corruption.

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.

More Use After Free vulnerabilities (CWE-416)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Other vulnerabilities in Safari

All Safari vulnerabilities

Recent Use After Free vulnerabilities

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