Vulnerability · Published Sep 14, 2026 · Assigned by apple

CVE-2026-84520

Critical 9.8

In plain English

A critical-severity buffer overflow in macOS from Apple. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 39% of all known vulnerabilities). Ready-made attack tooling exists: public proof-of-concept code.

Severity (CVSS 3.1)9.8Critical

Exploit odds (30 days)0.4%top 61.2% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack tooling1Public PoC

Official description

A buffer overflow was addressed with improved size validation. This issue is fixed in macOS Golden Gate 27. A local attacker may be able to cause unexpected system termination or corrupt kernel memory.

Affected products (as reported)

Vendor	Product	Versions
Apple	macOS	0 – before 27

Weakness: CWE-120 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

References

https://support.apple.com/en-us/149035