CVE-2021-21086

Name: CVE-2021-21086
Creator: NVD / NIST
Published: 2021-09-02T16:15:07.457+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 7.8/10EPSS 4.64%

Last modified Jun 17, 2026

CVE-2021-21086 is a high-severity vulnerability rated 7.8/10 on the CVSS scale. Acrobat Reader DC versions versions 2020.013.20074 (and earlier), 2020.001.30018 (and earlier) and 2017.011.30188 (and earlier) are affected by an Out-of-bounds Write vulnerability in the CoolType library. An unauthenticated attacker could leverage this vulnerability to achieve arbitrary code execution in the context of the current user. EPSS estimates a 4.64% chance of exploitation in the next 30 days.

Description

Acrobat Reader DC versions versions 2020.013.20074 (and earlier), 2020.001.30018 (and earlier) and 2017.011.30188 (and earlier) are affected by an Out-of-bounds Write vulnerability in the CoolType library. An unauthenticated attacker could leverage this vulnerability to achieve arbitrary code execution in the context of the current user. Exploitation of this issue requires user interaction in that a victim must open a malicious file.

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

4.64%

90.5th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Adobe	Acrobat	>= 17.011.30056, <= 17.011.30188
Adobe	Acrobat	>= 20.001.30005, <= 20.001.30018
Adobe	Acrobat Dc	>= 20.006.20042, <= 20.013.20074
Adobe	Acrobat Reader	>= 17.011.30059, <= 17.011.30188
Adobe	Acrobat Reader	>= 20.001.30005, <= 20.001.300183
Adobe	Acrobat Reader Dc	>= 20.006.20042, <= 20.013.20074

References

https://helpx.adobe.com/security/products/acrobat/apsb21-09.htmlVendor Advisory
https://helpx.adobe.com/security/products/acrobat/apsb21-09.htmlVendor Advisory

Timeline

Published: Sep 2, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-21086?

How severe is CVE-2021-21086?

CVE-2021-21086 has a CVSS score of 7.8/10 (HIGH severity). The EPSS model estimates a 4.64% probability of exploitation in the next 30 days.

How do I fix CVE-2021-21086?

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-2021-21086?

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

Scan your code now

Source: NVD / NIST