What is CVE-2026-84609?

CVE-2026-84609 is a critical-severity vulnerability in Apple iOS And Ipados, classified under Buffer Copy without Checking Size of Input (Classic Buffer Overflow). CVSS score: 9.8/10. Published 2026-09-14.

How severe is CVE-2026-84609?

Critical severity. CVSS v3 base score is 9.8 out of 10.

Buffer overflow in Apple iOS And Ipados

CVE-2026-84609

A permissions issue was addressed with improved path validation. This issue is fixed in iOS 27 and iPadOS 27, macOS Golden Gate 27, macOS Sequoia 15.8, macOS Tahoe 26.7, tvOS 27, visionOS 27, watchOS 27. An app may be able to modify protected system files.

Vulnerability class: Buffer Overflow

Published 2026-09-14 · last modified 2026-09-18.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.007 (51.7th percentile), scored 2026-10-30.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 52nd percentile — 51.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.007 · newest: 0.007 · change: 0.000

Affected products

Weakness classification (CWE)

CWE-120 — Buffer Copy without Checking Size of Input (Classic Buffer Overflow)

References

support.apple.com/en-us/149034 (Vendor Advisory)
support.apple.com/en-us/149035 (Vendor Advisory)
support.apple.com/en-us/149036 (Vendor Advisory)
support.apple.com/en-us/149037 (Vendor Advisory)
support.apple.com/en-us/149038 (Vendor Advisory)
support.apple.com/en-us/149042 (Vendor Advisory)
support.apple.com/en-us/149043 (Vendor Advisory)

Frequently asked questions

What is CVE-2026-84609?: CVE-2026-84609 is a critical-severity vulnerability in Apple iOS And Ipados, classified under Buffer Copy without Checking Size of Input (Classic Buffer Overflow). CVSS score: 9.8/10. Published 2026-09-14.
How severe is CVE-2026-84609?: Critical severity. CVSS v3 base score is 9.8 out of 10.