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Vulnerability record · public intelligence
CVE-2021-1840
HIGH

CVE-2021-1840

Published Sep 8, 2021 · Updated Oct 23, 2026

Severity · CVSSHIGH · 7.8
Known exploitationNot listed
EPSS / likelihood0.34%
QFinch risk score10 / 100

Original summary

Normalized public record · Updated Oct 23, 2026

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.

Publisher and source text is retained separately from QFinch interpretation.

QFinch assessment

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.

Evidence: public source records

Affected products

Affected scope reported by the available public evidence
Affected package, product or rangeFix status
Consult the referenced vendor advisory for affected versions.Consult source advisory

Matching a version is only one part of assessing exposure. QFinch has not assessed your environment on this public page.

Remediation

Apply the vendor-supported fixed release or mitigation, then verify the affected component is no longer reachable.

  1. Confirm the affected product and reachable code path exist in your environment.
  2. Apply the vendor-supported patch or mitigation from the primary advisory.
  3. Rescan the exact deployed revision and retain verification evidence.
Review primary references

Evidence coverage

CVENVDEPSS
SSVC priority
MEDIUM
Confidence
10%
Aliases
None reported

Scores appear only when corresponding evidence exists. Missing data is never interpreted as zero risk.

Sources and record history

  1. support.apple.com ↗
  2. support.apple.com ↗
  3. support.apple.com ↗

Record history

Published Sep 8, 2021 · Last refreshed Oct 23, 2026