CyberSecBulletin
CVE-2026-43661NVD status: Modified

iOS and iPadOS: Stack-based Buffer Overflow

Published Updated By the CyberSecBulletin desk

CVE-2026-43661 is a high-severity stack-based buffer overflow vulnerability in iOS and iPadOS 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 versions 18.7.10, 26.5, 26.7 as the first without the flaw, so updating iOS and iPadOS to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 1.26% chance of exploitation within 30 days, higher than 70% of scored CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update iOS and iPadOS to 18.7.10 or 26.5 or 26.7, whichever matches your release line, or a later version.
  2. Update macOS to 14.8.8 or 15.7.8 or 26.5, whichever matches your release line, or a later version.
  3. Update tvOS to 26.5 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.

Affected products and versions

VendorProductAffected versionsFixed in
AppleiOS and iPadOSbefore 18.7.10; before 26.5; before 26.718.7.10, 26.5, 26.7
ApplemacOSbefore 14.8.8; before 15.7.8; before 26.514.8.8, 15.7.8, 26.5
AppletvOSbefore 26.526.5
ApplewatchOSbefore 26.526.5
AppleiPadOSbefore 26.526.5
AppleIphone OSbefore 26.526.5

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
NoneNo data is disclosed.
Integrity
NoneNothing can be modified.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H. Scored by CISA (ADP).

Official description

A buffer overflow issue was addressed with improved memory handling. This issue is fixed in iOS 18.7.10 and iPadOS 18.7.10, iOS 26.5 and iPadOS 26.5, iOS 26.7 and iPadOS 26.7, macOS Sequoia 15.7.8, macOS Sonoma 14.8.8, macOS Tahoe 26.5, tvOS 26.5, watchOS 26.5. Processing a maliciously crafted image may corrupt process memory.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Stack-based Buffer Overflow

The product writes past the end of a buffer that was allocated on the stack.

How developers prevent this class of flaw

  • Use automatic buffer overflow detection mechanisms that are offered by certain compilers or compiler extensions. Examples include: the Microsoft Visual Studio /GS flag, Fedora/Red Hat FORTIFY_SOURCE GCC flag, StackGuard, and ProPolice, which provide various mechanisms including canary-based detection and range/index checking. D3-SFCV (Stack Frame Canary Validation) from D3FEND discusses canary-based detection in detail.
  • Use an abstraction library to abstract away risky APIs. Not a complete solution.
  • Implement and perform bounds checking on input.

More Stack-based Buffer Overflow vulnerabilities (CWE-121)

Timeline

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

References

Other vulnerabilities in iOS and iPadOS

All iOS and iPadOS vulnerabilities

Recent Stack-based Buffer Overflow vulnerabilities

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