SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityModified

CVE-2021-30765

An out-of-bounds write was addressed with improved input validation.

HIGH 7.8EPSS 1.33%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (1.33%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

An out-of-bounds write was addressed with improved input validation. This issue is fixed in macOS Big Sur 11.5, Security Update 2021-004 Catalina, Security Update 2021-005 Mojave. An application may be able to execute arbitrary code with kernel privileges.

CVSS 3.1
7.8 HIGHCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
EPSS
1.33% probability · 71th percentile
Public exploits
None in Exploit-DB
CISA KEV
Not listed
Weakness
CWE-787
Affected
apple/mac os x · apple/macos
Source
product-security@apple.com
EPSS trend
0%3%5%26 October 2026: 1.33%26 October 202626 October 2026

EPSS 1.3% since 26 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.

Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.