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Fencer Vulns
high 7.8

CVE-2021-39840 in the critical feed json

Adobe Acrobat Reader DC AcroForm Field Use-After-Free Remote Code Execution Vulnerability

published 2021-09-29 5 y ago modified 2026-06-17 4 mo ago also EUVD-2021-26197

cvss
7.8
version 3.0, CNA
cisa kev
Not listed
not in CISA's catalog
epss
60.8%
EPSS 60.8% chance of exploitation in 30 days, percentile 99.1%
public exploits
0
none known

Summary

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.

Exploit prediction

60.80% chance of exploitation in the next 30 days, higher than 99.1% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.0 7.8 CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
NVD 2.0 6.8 AV:N/AC:M/Au:N/C:P/I:P/A:P

Affected products

  • Adobe Acrobat Reader

Classification

Weakness

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.