CVE-2021-39851

Name: CVE-2021-39851
Creator: NVD / NIST
Published: 2021-09-29T16:15:10.073+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 5.5/10EPSS 1.88%

Last modified Jun 17, 2026

CVE-2021-39851 is a medium-severity vulnerability rated 5.5/10 on the CVSS scale. Acrobat Reader DC versions 2021.005.20060 (and earlier), 2020.004.30006 (and earlier) and 2017.011.30199 (and earlier) are affected by a Null pointer dereference vulnerability. An unauthenticated attacker could leverage this vulnerability to achieve an application denial-of-service in the context of the current user. EPSS estimates a 1.88% chance of exploitation in the next 30 days.

Description

Acrobat Reader DC versions 2021.005.20060 (and earlier), 2020.004.30006 (and earlier) and 2017.011.30199 (and earlier) are affected by a Null pointer dereference vulnerability. An unauthenticated attacker could leverage this vulnerability to achieve an application denial-of-service 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

5.5/10

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

EPSS Probability

1.88%

76.8th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-476

Affected Software

Vendor	Product	Versions
Adobe	Acrobat	>= 20.001.30005, <= 20.004.30006
Adobe	Acrobat Reader	>= 20.001.30005, <= 20.004.30006
Adobe	Acrobat Dc	>= 15.008.20082, <= 21.005.20058
Adobe	Acrobat Reader Dc	>= 15.008.20082, <= 21.005.20058
Adobe	Acrobat Dc	>= 15.008.20082, <= 21.005.20060
Adobe	Acrobat Reader Dc	>= 15.008.20082, <= 21.005.20060
Adobe	Acrobat	>= 17.011.30059, <= 17.011.30199
Adobe	Acrobat Reader	>= 17.011.30059, <= 17.011.30199

References

https://helpx.adobe.com/security/products/acrobat/apsb21-55.htmlRelease Notes, Vendor Advisory
https://helpx.adobe.com/security/products/acrobat/apsb21-55.htmlRelease Notes, Vendor Advisory

Timeline

Published: Sep 29, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-39851?

How severe is CVE-2021-39851?

CVE-2021-39851 has a CVSS score of 5.5/10 (MEDIUM severity). The EPSS model estimates a 1.88% probability of exploitation in the next 30 days.

How do I fix CVE-2021-39851?

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-2021-39851?

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

Scan your code now

Source: NVD / NIST