No exploitation reportedFix available

CVE-2021-1828

Q: Is CVE-2021-1828 actively exploited?

Active exploitation of CVE-2021-1828 has not been confirmed. Its EPSS score was 1.0% on 2026-10-22, the estimated probability of exploitation in the next 30 days.

Q: What is the CVSS score for CVE-2021-1828?

CVE-2021-1828 has a CVSS v3 base score of 7.1 (HIGH severity), with vector string CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:H.

No exploitation reported by the sources we read.

Published2021-09-08
WeaknessCWE-787

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 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. An application may be able to cause unexpected system termination or write kernel memory.

Timeline

dates in UTC

2021-09-0815:15CVE publishedNVD

Observed activity

isMalicious corpus · updated 2026-10-23 21:37 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-2021-1828?format=txt
CSV export: https://api.ismalicious.com/edl/cve/CVE-2021-1828?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, ≤ 10.15.5	no fix published	NVD
10.14	= 10.14.6	no fix published	NVD
10.15	= 10.15.6	no fix published	NVD
10.15	= 10.15.7	no fix published	NVD

Apple macos

Branch	Affected	Fixed in	Source
11.x	≥ 11.0, < 11.3	11.3	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 3.17.1read 2026-10-23
NVDCVSS 2.08.8read 2026-10-23
NVDweakness (CWE)CWE-787read 2026-10-23
FIRST EPSSEPSS score1.0 %2026-10-22

Technical details

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

Frequently asked questions

What is CVE-2021-1828?

Is CVE-2021-1828 actively exploited?

Active exploitation of CVE-2021-1828 has not been confirmed. Its EPSS score was 1.0% on 2026-10-22, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2021-1828?

CVE-2021-1828 has a CVSS v3 base score of 7.1 (HIGH severity), with vector string CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:H.

Hear about the next vulnerability in your software

Surveillance reads the versions in your stack — a domain, a lockfile or a list — checks each CVE against the ranges its sources publish, and alerts you when one you run is exploited or enters CISA KEV. A version it cannot read stays « version not verified ».

Get alerts for this product CISA KEV additions, October 2026 Search CVEs

No credit card required · No monthly cap on website lookups · 250 API requests/month

Go further

Following what attackers exploit right now? The CISA KEV additions of the month, with their patch deadlines.
Running this software? Vulnerability monitoring alerts you to new vulnerabilities in your products.

Related vulnerabilities

Same product first, then the same vendor advisory and the same publication week.

Back to CVE Database