Actively exploited vulnerability

Apple iOS, iPadOS, and macOS: memory corruption flaw under attack

CVE-2025-43300 · Apple iOS, iPadOS, and macOS Out-of-Bounds Write Vulnerability

Concerns everyone who uses it10.0 critical

What is affected

Apple iOS, iPadOS, and macOS is found on ordinary personal computers and phones, so this is not only a problem for companies. If you use it and have not updated since the fix was released, you are exposed.

Apple iOS, iPadOS, and macOS contain an out-of-bounds write vulnerability in the Image I/O framework.

CISA's description

What an attacker can do

This is a memory corruption flaw. It lets an attacker corrupt the program's memory by feeding it specially crafted content: a web page, a file or a network message. The result ranges from a crash to the attacker running their own code.

How it is reached
Over the internet or network
Access the attacker needs
No account needed
Does the victim have to do something?
No, works without the victim doing anything

What to do

  1. Update Apple iOS, iPadOS, and macOS now. Open the update or "About" screen, install whatever is offered and restart the app or device, because the fix is not active until you do.
  2. Turn on automatic updates so the next fix arrives without you having to look for it.
  3. If your device is too old to receive this update, stop using the affected app for anything sensitive and plan a replacement.

Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

Action required by CISA for US federal agencies

Vendor advisories and fixes

How urgent is it

CISA added this vulnerability to its Known Exploited Vulnerabilities catalogue on August 21, 2025, which means there is reliable evidence of attacks in the wild. US federal agencies must fix it by September 11, 2025, a deadline that has already passed. That deadline does not bind anyone else, but it shows how seriously the agency rates it.

The EPSS model estimates a 32% probability that this flaw will be exploited somewhere in the next 30 days. That is higher than 98% of all scored vulnerabilities.

Its CVSS severity score is 10.0 out of 10 (critical), as recorded in the US National Vulnerability Database.

Technical description

An out-of-bounds write issue was addressed with improved bounds checking. This issue is fixed in iOS 15.8.5 and iPadOS 15.8.5, iOS 16.7.12 and iPadOS 16.7.12, iOS 18.6.2 and iPadOS 18.6.2, iPadOS 17.7.10, macOS Sequoia 15.6.1, macOS Sonoma 14.7.8, macOS Ventura 13.7.8. Processing a malicious image file may result in memory corruption. Apple is aware of a report that this issue may have been exploited in an extremely sophisticated attack against specific targeted individuals.

NIST National Vulnerability Database
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