How severe is CVE-2021-30765?

CVE-2021-30765 has a CVSS 3.x base score of 7.8, rated high severity. It is exploitable over local access with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2021-30765 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (68th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-30765?

CVE-2021-30765 primarily affects Apple Mac Os X. In total, 46 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-30765?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2021-30765 published?

CVE-2021-30765 was published on 2021-09-08 and last updated on 2026-06-17.

CVE-2021-30765

CVE-2021-30765 is a high-severity vulnerability in Apple Mac Os X with a CVSS 3.x base score of 7.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-787.

Key facts

Severity: High (CVSS 3.x base score 7.8)
CVSS v2: 9.3
EPSS exploit prediction: 1% (68th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-787
Affected product: Apple Mac Os X
Published: 2021-09-08
Last modified: 2026-06-17

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.

Frequently asked questions

What is CVE-2021-30765?: 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.
How severe is CVE-2021-30765?: CVE-2021-30765 has a CVSS 3.x base score of 7.8, rated high severity. It is exploitable over local access with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2021-30765 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (68th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-30765?: CVE-2021-30765 primarily affects Apple Mac Os X. In total, 46 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-30765?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2021-30765 published?: CVE-2021-30765 was published on 2021-09-08 and last updated on 2026-06-17.

References

Affected products (46)

cpe:2.3:o:apple:mac_os_x:10.14:*:*:*:*:*:*:*
cpe:2.3:o:apple:mac_os_x:10.14.0:*:*:*:*:*:*:*
cpe:2.3:o:apple:mac_os_x:10.14.1:*:*:*:*:*:*:*
cpe:2.3:o:apple:mac_os_x:10.14.2:*:*:*:*:*:*:*
cpe:2.3:o:apple:mac_os_x:10.14.3:*:*:*:*:*:*:*
cpe:2.3:o:apple:mac_os_x:10.14.4:*:*:*:*:*:*:*
cpe:2.3:o:apple:mac_os_x:10.14.5:*:*:*:*:*:*:*
cpe:2.3:o:apple:mac_os_x:10.14.6:*:*:*:*:*:*:*
cpe:2.3:o:apple:mac_os_x:10.14.6:-:*:*:*:*:*:*
cpe:2.3:o:apple:mac_os_x:10.14.6:security_update_2019-001:*:*:*:*:*:*
cpe:2.3:o:apple:mac_os_x:10.14.6:security_update_2019-002:*:*:*:*:*:*
cpe:2.3:o:apple:mac_os_x:10.14.6:security_update_2019-004:*:*:*:*:*:*
cpe:2.3:o:apple:mac_os_x:10.14.6:security_update_2019-005:*:*:*:*:*:*
cpe:2.3:o:apple:mac_os_x:10.14.6:security_update_2019-006:*:*:*:*:*:*
cpe:2.3:o:apple:mac_os_x:10.14.6:security_update_2019-007:*:*:*:*:*:*
cpe:2.3:o:apple:mac_os_x:10.14.6:security_update_2020-001:*:*:*:*:*:*
cpe:2.3:o:apple:mac_os_x:10.14.6:security_update_2020-002:*:*:*:*:*:*
cpe:2.3:o:apple:mac_os_x:10.14.6:security_update_2020-003:*:*:*:*:*:*
cpe:2.3:o:apple:mac_os_x:10.14.6:security_update_2020-004:*:*:*:*:*:*
cpe:2.3:o:apple:mac_os_x:10.14.6:security_update_2020-005:*:*:*:*:*:*
cpe:2.3:o:apple:mac_os_x:10.14.6:security_update_2020-006:*:*:*:*:*:*
cpe:2.3:o:apple:mac_os_x:10.14.6:security_update_2020-007:*:*:*:*:*:*
cpe:2.3:o:apple:mac_os_x:10.14.6:security_update_2021-001:*:*:*:*:*:*
cpe:2.3:o:apple:mac_os_x:10.14.6:security_update_2021-002:*:*:*:*:*:*
cpe:2.3:o:apple:mac_os_x:10.14.6:security_update_2021-003:*:*:*:*:*:*
cpe:2.3:o:apple:mac_os_x:10.14.6:security_update_2021-004:*:*:*:*:*:*
cpe:2.3:o:apple:mac_os_x:10.14.6:supplemental_update:*:*:*:*:*:*
cpe:2.3:o:apple:mac_os_x:10.14.6:supplemental_update_2:*:*:*:*:*:*
cpe:2.3:o:apple:mac_os_x:10.15:*:*:*:*:*:*:*
cpe:2.3:o:apple:mac_os_x:10.15.1:*:*:*:*:*:*:*
cpe:2.3:o:apple:mac_os_x:10.15.2:*:*:*:*:*:*:*
cpe:2.3:o:apple:mac_os_x:10.15.3:*:*:*:*:*:*:*
cpe:2.3:o:apple:mac_os_x:10.15.4:*:*:*:*:*:*:*
cpe:2.3:o:apple:mac_os_x:10.15.5:*:*:*:*:*:*:*
cpe:2.3:o:apple:mac_os_x:10.15.6:*:*:*:*:*:*:*
cpe:2.3:o:apple:mac_os_x:10.15.6:supplemental_update:*:*:*:*:*:*
cpe:2.3:o:apple:mac_os_x:10.15.7:-:*:*:*:*:*:*
cpe:2.3:o:apple:mac_os_x:10.15.7:security_update_2020:*:*:*:*:*:*
cpe:2.3:o:apple:mac_os_x:10.15.7:security_update_2020-001:*:*:*:*:*:*
cpe:2.3:o:apple:mac_os_x:10.15.7:security_update_2020-005:*:*:*:*:*:*

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