CVE-2021-30766
An out-of-bounds write was addressed with improved input validation. This issue is fixed in macOS...
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.
Attack profile
How easy it is to exploit
- Attack vector
- Local
- Complexity
- Low
- Privileges needed
- None
- User interaction
- Required
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Exploit likelihood
What each source reports
NVD Score used
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.
- Record
CVE-2021-30766- CVSS 3.1
- 7.8 High
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H - CVSS 2.0
- 9.3 High
AV:N/AC:M/Au:N/C:C/I:C/A:C - Weakness
- CWE-787
- Updated
- 2026-11-02
CVE ListNo score
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.
- Record
CVE-2021-30766- Updated
- 2026-11-02
EUVDEUVD-2021-17683No score
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.
- Record
EUVD-2021-17683- Updated
- 2026-11-03
GitHub AdvisoriesGHSA-964m-f4fc-h2mfNo score
An out-of-bounds write was addressed with improved input validation. This issue is fixed in macOS...
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.
- Record
GHSA-964m-f4fc-h2mf- Weakness
- CWE-787
- Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2021-30766 is a high vulnerability (CVSS 7.8) in Apple Macos, published September 8, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 1.33%, the 71st percentile. No source names a fixed version.