# CVE-2021-39840: Adobe Acrobat Reader DC AcroForm Field Use-After-Free Remote Code Execution Vulnerability

CVE-2021-39840 is fixed in Adobe Acrobat Reader DC on 1 platform by Adobe Acrobat Reader DC 21.007.20091 (version 21.007.20091), released September 9, 2021. It is not reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/cve/CVE-2021-39840
- Priority: High
- CVSS: 7.8
- EPSS: 0.6080
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Sep 29, 2021
- Weakness: CWE-416: Use After Free (CWE-416)
- Vendor advisory: https://nvd.nist.gov/vuln/detail/CVE-2021-39840

## 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 use-after-free vulnerability when processing AcroForms that could result in arbitrary code execution in the context of the current user. User interaction is required to exploit this vulnerability in that the target must visit a malicious page or open a malicious file.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Windows apps | Adobe Acrobat Reader DC | 21.007.20091 | [Adobe Acrobat Reader DC 21.007.20091](https://patchblox.com/security/data/fix/windows-app/adobe.acrobat.reader.32-bit-21.007.20091.md) | Sep 9, 2021 |

---

Data as of 2026-11-08T13:06:02Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

Free to use with attribution: show "Data: Patchblox Patch Radar" with a link to https://patchblox.com/security/patch-radar. Terms, including what needs a written agreement: https://patchblox.com/security/patch-radar/use-the-data

Product names, logos and trademarks shown on Patch Radar belong to their respective owners. They are used only to identify the software each security fix applies to and to help readers find their platform. Their use does not imply any affiliation with, or endorsement by, those owners, and Patchblox is not affiliated with any of them.