CVE-2021-1840

HIGHNVD 7.87.8—

7.8

A memory corruption issue was addressed with improved validation. This issue is fixed in macOS Big Sur 11.3, Security Update 2021-002 Catalina, Security Update 2021-003 Mojave. A local attacker may be able to elevate their privileges.

CVSS v3: 7.8
EG Score: 7.8(medium)
EPSS: 21.3%
KEV: Not listed

Published

September 8, 2021

Last Modified

November 21, 2024

References (6)

product-security@applehttps://support.apple.com/en-us/HT212325
product-security@applehttps://support.apple.com/en-us/HT212326
product-security@applehttps://support.apple.com/en-us/HT212327
af854a3a-2127-422b-91ae-364da2661108https://support.apple.com/en-us/HT212325
af854a3a-2127-422b-91ae-364da2661108https://support.apple.com/en-us/HT212326
af854a3a-2127-422b-91ae-364da2661108https://support.apple.com/en-us/HT212327

Weakness Classification(2)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 13× in last 7d / 20× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

2026-06-08 14:15 UTCEPSS rescore
2026-06-08 14:15 UTCEPSS rescore
2026-06-07 15:23 UTCEPSS rescore
2026-06-07 15:23 UTCEPSS rescore
2026-06-06 13:46 UTCEPSS rescore
2026-06-06 13:46 UTCEPSS rescore
2026-06-06 13:46 UTCEPSS rescore
2026-06-05 22:45 UTCEPSS rescore
2026-06-05 22:45 UTCEPSS rescore
2026-06-05 06:09 UTCEPSS rescore
2026-06-05 06:09 UTCEPSS rescore
2026-06-05 06:08 UTCEPSS rescore
2026-06-04 13:10 UTCEPSS rescore
2026-06-02 20:11 UTCEPSS rescore
2026-06-02 20:11 UTCEPSS rescore
2026-06-01 13:50 UTCEPSS rescore
2026-06-01 13:50 UTCEPSS rescore
2026-05-31 22:29 UTCEPSS rescore
2026-05-31 22:29 UTCEPSS rescore
2026-05-31 00:15 UTCEPSS rescore

Frequently asked(5)

What is CVE-2021-1840?

CVE-2021-1840 is a high vulnerability published on September 8, 2021. A memory corruption issue was addressed with improved validation. This issue is fixed in macOS Big Sur 11.3, Security Update 2021-002 Catalina, Security Update 2021-003 Mojave. A local attacker may be able to elevate their privileges.

When was CVE-2021-1840 disclosed?

CVE-2021-1840 was first published in the National Vulnerability Database on September 8, 2021, with the most recent update on November 21, 2024. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.

Is CVE-2021-1840 actively exploited?

CVE-2021-1840 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 21.3% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.

What is the CVSS score of CVE-2021-1840?

CVE-2021-1840 has a CVSS v3 base score of 7.8 (NVD).

How do I remediate CVE-2021-1840?

Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2021-1840, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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CVE-2021-1840

📅 Published

🔄 Last Modified

🔗 References (6)

Weakness Classification(2)

Data Freshness Timeline

❓ Frequently asked(5)

Dependency Blast Radius

Is Your Infrastructure Affected by CVE-2021-1840?

🔗 Related CVEs(same CWE)

Same CWE

Published

Last Modified

References (6)

Frequently asked(5)

Related CVEs(same CWE)