How severe is CVE-2021-30865?

CVE-2021-30865 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-2021-30865 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (60th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-30865?

CVE-2021-30865 primarily affects Apple Mac Os X. In total, 9 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-30865?

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-2021-30865 published?

CVE-2021-30865 was published on 2021-08-24 and last updated on 2026-06-17.

CVE-2021-30865

CVE-2021-30865 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-125.

Key facts

Severity: High (CVSS 3.x base score 7.8)
CVSS v2: 9.3
EPSS exploit prediction: 1% (60th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-125
Affected product: Apple Mac Os X
Published: 2021-08-24
Last modified: 2026-06-17

Description

An out-of-bounds read was addressed with improved input validation. This issue is fixed in macOS Big Sur 11.6, Security Update 2021-005 Catalina. A malicious application may be able to execute arbitrary code with kernel privileges.

Frequently asked questions

What is CVE-2021-30865?: An out-of-bounds read was addressed with improved input validation. This issue is fixed in macOS Big Sur 11.6, Security Update 2021-005 Catalina. A malicious application may be able to execute arbitrary code with kernel privileges.
How severe is CVE-2021-30865?: CVE-2021-30865 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-2021-30865 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (60th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-30865?: CVE-2021-30865 primarily affects Apple Mac Os X. In total, 9 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-30865?: 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-2021-30865 published?: CVE-2021-30865 was published on 2021-08-24 and last updated on 2026-06-17.

References

Affected products (9)

cpe:2.3:o:apple:mac_os_x:*:*:*:*:*:*:*:*
cpe:2.3:o:apple:mac_os_x:10.15.7:-:*:*:*:*:*:*
cpe:2.3:o:apple:mac_os_x:10.15.7:security_update_2020-001:*:*:*:*:*:*
cpe:2.3:o:apple:mac_os_x:10.15.7:security_update_2021-001:*:*:*:*:*:*
cpe:2.3:o:apple:mac_os_x:10.15.7:security_update_2021-002:*:*:*:*:*:*
cpe:2.3:o:apple:mac_os_x:10.15.7:security_update_2021-003:*:*:*:*:*:*
cpe:2.3:o:apple:mac_os_x:10.15.7:security_update_2021-004:*:*:*:*:*:*
cpe:2.3:o:apple:mac_os_x:10.15.7:supplemental_update:*:*:*:*:*:*
cpe:2.3:o:apple:macos:*:*:*:*:*:*:*:*

More vulnerabilities in Apple Mac Os X

CVE-2018-4310 — Critical (CVSS 10.0): An access issue was addressed with additional sandbox restrictions. This issue affected versions prior to iOS 12, macOS…
CVE-2019-6235 — Critical (CVSS 10.0): A memory corruption issue was addressed with improved validation. This issue is fixed in iOS 12.1.3, macOS Mojave…
CVE-2018-4229 — Critical (CVSS 10.0): An issue was discovered in certain Apple products. macOS before 10.13.5 is affected. The issue involves the "Grand…
CVE-2018-4091 — Critical (CVSS 10.0): An issue was discovered in certain Apple products. macOS before 10.13.3 is affected. The issue involves the "Sandbox"…
CVE-2015-8659 — Critical (CVSS 10.0): The idle stream handling in nghttp2 before 1.6.0 allows attackers to have unspecified impact via unknown vectors, aka a…
CVE-2015-7071 — Critical (CVSS 10.0): The File Bookmark component in Apple OS X before 10.11.2 allows attackers to bypass a sandbox protection mechanism for…

All CVEs affecting Apple Mac Os X →

Other CWE-125 (Out-of-bounds Read) vulnerabilities

CVE-2026-24826 — Critical (CVSS 10.0): Out-of-bounds Write, Divide By Zero, NULL Pointer Dereference, Use of Uninitialized Resource, Out-of-bounds Read,…
CVE-2024-22004 — Critical (CVSS 10.0): Due to length check, an attacker with privilege access on a Linux Nonsecure operating system can trigger a…
CVE-2021-41556 — Critical (CVSS 10.0): sqclass.cpp in Squirrel through 2.2.5 and 3.x through 3.1 allows an out-of-bounds read (in the core interpreter) that…
CVE-2021-21777 — Critical (CVSS 10.0): An information disclosure vulnerability exists in the Ethernet/IP UDP handler functionality of EIP Stack Group OpENer…
CVE-2017-14451 — Critical (CVSS 10.0): An exploitable out-of-bounds read vulnerability exists in libevm (Ethereum Virtual Machine) of CPP-Ethereum. A…
CVE-2013-0767 — Critical (CVSS 10.0): The nsSVGPathElement::GetPathLengthScale function in Mozilla Firefox before 18.0, Firefox ESR 10.x before 10.0.12 and…

Browse all CWE-125 (Out-of-bounds Read) vulnerabilities →