CVE-2025-43520
CVE-2025-43520 is a security flaw in Apple devices, the software on Apple’s iPhones, iPads and Macs. Attackers can corrupt memory in Apple devices, which they use to take it over. The US Cybersecurity and Infrastructure Security Agency (CISA) added it to its catalog of flaws known to be used in attacks on 20 Mar 2026.[1]
Apple devices is in things households have, such as phones, computers, browsers and everyday apps, so the fix matters at home as much as at work. Fixed in version 18.7.2, 26.1, 14.8.2 and 15.7.2.
Description
CISA calls it a classic buffer overflow in Apple Multiple Products. In its words: “Apple watchOS, iOS, iPadOS, macOS, visionOS, and tvOS contain a classic buffer overflow vulnerability which could allow a malicious application to cause unexpected system termination or write kernel memory.”[1]
The CVE record adds: “A memory corruption issue was addressed with improved memory handling. This issue is fixed in iOS 18.7.2 and iPadOS 18.7.2, iOS 26.1 and iPadOS 26.1, macOS Sequoia 15.7.2, macOS Sonoma 14.8.2, macOS Tahoe 26.1, tvOS 26.1, visionOS 26.1, watchOS 26.1. A malicious application may be able to cause unexpected system termination or write kernel memory.”[2]
The underlying weakness is buffer overflow (CWE-120), in MITRE’s list of common software weaknesses.
It scores 5.5 out of 10 on the Common Vulnerability Scoring System, which rates it medium, scored by NVD using CVSS 3.1.[2]
Affected versions
NVD’s record lists these fixed versions: in each line, everything before the version shown is affected.[2]
| Product | Fixed in |
|---|---|
| iOS and iPadOS | 18.7.2 |
| iOS and iPadOS | 26.1 |
| macOS | 14.8.2 |
| macOS | 15.7.2 |
| macOS | 26.1 |
| tvOS | 26.1 |
| visionOS | 26.1 |
| watchOS | 26.1 |
Every device with Apple devices needs the update.
Exploitation
CISA added it to its catalog of known exploited vulnerabilities on 20 Mar 2026, 98 days after it was made public. CISA lists a flaw only when it has reliable evidence of it being exploited, and gave US federal agencies until 3 Apr 2026 to fix it.[1]
FIRST’s Exploit Prediction Scoring System, which estimates how likely a flaw is to be used in attacks in the next 30 days from what it sees across the internet, puts it at under 1%. That’s in the top 64% of the flaws it scores.[4]
CISA assesses it as not automatable: each attack takes some work.
CISA doesn’t say who was attacked, or how.
Fix
Apple has published a fix or advice.[3] 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.”[1]
- Update Apple devices now.On iPhone and iPad: Settings, General, Software Update. On a Mac: System Settings, General, Software Update. Install it on every Apple device in the house. Then turn on automatic updates, so the next fix arrives on its own.
- Check you’re on 18.7.2 or later.Fixed in version 18.7.2, 26.1, 14.8.2 and 15.7.2. Anything older is what attackers are going after.
- If there’s no update, stop using it.CISA’s advice when a flaw being used in attacks has no fix is to stop using the product until it does.
Timeline
| Date | Event |
|---|---|
| The flaw is made public in the National Vulnerability Database, with a severity score of 5.5.[2] | |
| CISA adds it to its catalog of flaws known to be used in attacks.[1] | |
| CISA’s deadline for US government agencies to fix it.[1] | |
| FIRST puts the odds of it being used in attacks in the next 30 days at under 1%.[4] |
See also
Other Apple devices flaws
- CVE-2026-86950: out-of-bounds write ·
- CVE-2025-43510: improper locking ·
- CVE-2025-31277: buffer overflow ·
- CVE-2023-43000: use-after-free ·
- CVE-2021-30952: integer overflow or wraparound ·
- CVE-2026-20700: multiple buffer overflow ·
Other buffer overflow flaws
- CVE-2022-37055, D-Link Routers: buffer overflow ·
- CVE-2025-20333, Cisco Secure Firewall Adaptive Security Appliance and Secure Firewall Threat Defense: secure firewall adaptive security appliance (ASA) and secure firewall threat defense (FTD) buffer overflow ·
- CVE-2020-15069, Sophos XG Firewall: buffer overflow ·
- CVE-2023-33010, Zyxel Multiple Firewalls: buffer overflow ·
- CVE-2023-33009, Zyxel Multiple Firewalls: buffer overflow ·
Added the same day
- CVE-2025-54068, Laravel Livewire: code injection ·
- CVE-2025-43510, Apple devices: improper locking ·
- CVE-2025-32432, Craft CMS: code injection ·
- CVE-2025-31277, Apple devices: buffer overflow ·
Every Apple flaw on CISA’s list · Everything added in March 2026
References
- ^ Cybersecurity and Infrastructure Security Agency. “Apple Multiple Products Classic Buffer Overflow Vulnerability”. Known Exploited Vulnerabilities Catalog, added 20 Mar 2026.
- ^ National Institute of Standards and Technology. “CVE-2025-43520 Detail”. National Vulnerability Database, published 12 Dec 2025.
- ^ Apple. Advisories and fixes: support.apple.com, support.apple.com, support.apple.com, support.apple.com, support.apple.com, and 3 more on NVD’s record.
- ^ FIRST. “Exploit Prediction Scoring System”. EPSS 0.004, percentile 36.8, 31 Oct 2026.
- CVE Program. “CVE-2025-43520”. The official CVE record.
This article is built from CISA’s catalog (version 2026.10.30), NVD’s record and FIRST’s scores, kept in HARD’s database and checked every morning. The plain English is HARD’s.