CVE-2021-30939

Name: CVE-2021-30939
Creator: NVD / NIST
Published: 2021-08-24T19:15:21.093+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 7.8/10EPSS 4.06%

Last modified Jun 17, 2026

CVE-2021-30939 is a high-severity vulnerability rated 7.8/10 on the CVSS scale. An out-of-bounds read was addressed with improved bounds checking. This issue is fixed in macOS Big Sur 11.6.2, tvOS 15.2, macOS Monterey 12.1, Security Update 2021-008 Catalina, iOS 15.2 and iPadOS 15.2, watchOS 8.3. EPSS estimates a 4.06% chance of exploitation in the next 30 days.

Description

An out-of-bounds read was addressed with improved bounds checking. This issue is fixed in macOS Big Sur 11.6.2, tvOS 15.2, macOS Monterey 12.1, Security Update 2021-008 Catalina, iOS 15.2 and iPadOS 15.2, watchOS 8.3. Processing a maliciously crafted image may lead to arbitrary code execution.

Metrics

CVSS 3.1

7.8/10

CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

EPSS Probability

4.06%

89.4th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-125

Affected Software

Vendor	Product	Versions
Apple	Ipados	< 15.2
Apple	Iphone Os	< 15.2
Apple	Mac Os X	>= 10.15, < 10.15.7
Apple	Mac Os X	10.15.7
Apple	Macos	>= 11.0, < 11.6.2
Apple	Macos	>= 12.0, < 12.1
Apple	Tvos	< 15.2
Apple	Watchos	< 8.3

References

Timeline

Published: Aug 24, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-30939?

How severe is CVE-2021-30939?

CVE-2021-30939 has a CVSS score of 7.8/10 (HIGH severity). The EPSS model estimates a 4.06% probability of exploitation in the next 30 days.

How do I fix CVE-2021-30939?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-30939?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST