No exploitation reportedFix available

CVE-2021-30678

Q: Is CVE-2021-30678 actively exploited?

Active exploitation of CVE-2021-30678 has not been confirmed. Its EPSS score was 3.3% on 2026-10-22, the estimated probability of exploitation in the next 30 days.

Q: What is the CVSS score for CVE-2021-30678?

CVE-2021-30678 has a CVSS v3 base score of 9.8 (CRITICAL severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

No exploitation reported by the sources we read.

Published2021-09-08

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

Description

A logic issue was addressed with improved state management. This issue is fixed in macOS Big Sur 11.4, Security Update 2021-003 Catalina, Security Update 2021-004 Mojave. A remote attacker may be able to cause unexpected application termination or arbitrary code execution.

Timeline

dates in UTC

2021-09-0815:15CVE publishedNVD

Observed activity

isMalicious corpus · updated 2026-10-23 18:48 UTC

Indicators tagged with this CVE, per day0 indicators over 7 days

Block these indicators

Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2021-30678?format=txt
CSV export: https://api.ismalicious.com/edl/cve/CVE-2021-30678?format=csv
TAXII collection of exploited CVEs
The EDL and CSV take an API key on the Pro plan.

Versions per branch

NVD

Apple mac os x

Branch	Affected	Fixed in	Source
10.14	≥ 10.14, ≤ 10.14.5	no fix published	NVD
10.15	≥ 10.15, ≤ 10.15.6	no fix published	NVD
10.14	= 10.14.6	no fix published	NVD
10.15	= 10.15.7	no fix published	NVD

Apple macos

Branch	Affected	Fixed in	Source
11.x	≥ 11.0, < 11.4	11.4	NVD

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Fix

Advisories and patches

support.apple.comVendor Advisory
support.apple.comVendor Advisory
support.apple.comVendor Advisory

Detection

Nuclei template: none so far
Exploit-DB: no entry
Proof-of-concept repositories: none listed

Sources

NVDCVSS 3.19.8read 2026-10-23
NVDCVSS 2.07.5read 2026-10-23
FIRST EPSSEPSS score3.3 %2026-10-22

Technical details

CVSS v3 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Published: 2021-09-08
Last Modified: 2026-06-17
NVD status: Modified

Frequently asked questions

What is CVE-2021-30678?

Is CVE-2021-30678 actively exploited?

Active exploitation of CVE-2021-30678 has not been confirmed. Its EPSS score was 3.3% on 2026-10-22, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2021-30678?

CVE-2021-30678 has a CVSS v3 base score of 9.8 (CRITICAL severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

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