What is CVE-2025-43400?

CVE-2025-43400 is a medium-severity vulnerability in Apple iOS And Ipados, classified under Out-of-bounds Write. CVSS score: 6.3/10. Published 2025-09-29.

How severe is CVE-2025-43400?

Medium severity. CVSS v3 base score is 6.3 out of 10.

Is CVE-2025-43400 known to be exploited?

3 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.

Buffer overflow in Apple iOS And Ipados

CVE-2025-43400

An out-of-bounds write issue was addressed with improved bounds checking. This issue is fixed in iOS 18.7.1 and iPadOS 18.7.1, iOS 26.0.1 and iPadOS 26.0.1, macOS Sequoia 15.7.1, macOS Sonoma 14.8.1, macOS Tahoe 26.0.1, tvOS 26.1, visionOS 26.0.1, watchOS 26.1. Processing a maliciously crafted font may lead to unexpected app termination or corrupt process memory.

Vulnerability class: Buffer Overflow

EPSS: 0.064 (93.0th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 6.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:L.

Affected products

Apple Ios And Ipados — versions 0
Apple Ipados — versions 26.0
Apple Iphone_os — versions 26.0
Apple Macos — versions 26.0, 0
Apple Tvos — versions 0
Apple Visionos — versions 0
Apple Watchos — versions 0

Weakness classification (CWE)

CWE-787 — Out-of-bounds Write

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2025-43400?: CVE-2025-43400 is a medium-severity vulnerability in Apple iOS And Ipados, classified under Out-of-bounds Write. CVSS score: 6.3/10. Published 2025-09-29.
How severe is CVE-2025-43400?: Medium severity. CVSS v3 base score is 6.3 out of 10.
Is CVE-2025-43400 known to be exploited?: 3 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.