Critical severity · published Jul 27, 2026
CVE-2026-64691
A buffer overflow was addressed with improved size validation
9.8
CVSS
0.5%
EPSS
No
On KEV
Description
A buffer overflow was addressed with improved size validation. This issue is fixed in macOS Tahoe 26.6. An app may be able to cause unexpected system termination.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
High
Integrity
High
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.5% · higher than 40% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
MA
macOS · Apple
before 26.6 · source: vendor, NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-64691
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-64691
Release Notes
https://support.apple.com/en-us/128067
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