What is CVE-2021-1829?

CVE-2021-1829 is a critical-severity vulnerability in Apple macOS, classified under Access of Resource Using Incompatible Type (Type Confusion). CVSS score: 9.8/10. Published 2021-09-08.

How severe is CVE-2021-1829?

Critical severity. CVSS v3 base score is 9.8 out of 10.

Is CVE-2021-1829 known to be exploited?

1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.

Vulnerability in Apple macOS

CVE-2021-1829

A type confusion issue was addressed with improved state handling. This issue is fixed in macOS Big Sur 11.3. An application may be able to execute arbitrary code with kernel privileges.

Published 2021-09-08 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.023 (82.4th percentile), scored 2026-10-02.

Low probability of exploitation in the next 30 days, but still tracked. 82nd percentile — 82.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.023 · newest: 0.023 · change: 0.000

Affected products

Apple macOS — versions unspecified

Weakness classification (CWE)

CWE-843 — Access of Resource Using Incompatible Type (Type Confusion)

Public proof-of-concept exploits

n0-traces/cve_

References

support.apple.com/en-us/HT212325 (Release Notes, Vendor Advisory)

Frequently asked questions

What is CVE-2021-1829?: CVE-2021-1829 is a critical-severity vulnerability in Apple macOS, classified under Access of Resource Using Incompatible Type (Type Confusion). CVSS score: 9.8/10. Published 2021-09-08.
How severe is CVE-2021-1829?: Critical severity. CVSS v3 base score is 9.8 out of 10.
Is CVE-2021-1829 known to be exploited?: 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.