CVE-2021-39840

mediumpriority · attend · 48EPSS 0.608 · 99 %ileEURUUS

grimoire priorityP1 · Urgent

Exploitable?

—

no known exploitation

Likely / severe?

60.8% (99th) EPSS

CVSS 6.8 · medium

Is it mine?

18 products

Check your exposure

Who says so?

4 sources

cnnvd · enisa_euvd · fstec_bdu · nvd

EPSS · scored 2026-10-27

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.

cvss

Technical severity, 0–10. One row per scoring source.

8.8

010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–high · 6.8–8.8

v2.06.8mediumAV:N/AC:M/Au:N/C:P/I:P/A:Pprimary · NVD / NIST USexploitability 8.6 · impact 6.4

v2.06.8mediumAV:N/AC:M/Au:N/C:P/I:P/A:P/E:Hsecondary · CVSS-BT (t0sche)

v3.07.8highCVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:Hsecondary · ENISA EU

v3.07.8highCVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:Hsecondary · psirt@adobe.comexploitability 1.8 · impact 5.9

v3.18.8highAV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:Hsecondary · FSTEC (BDU) RU

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-416USCWE-416US

affected products (18)

Products and version ranges known to be affected.

Adobe Acrobat Reader≤ unspecified ≤Noneenisa_euvdEU
Adobe Acrobat Reader≤ unspecified ≤DC 2021 Julyenisa_euvdEU
Adobe Acrobat Reader≤ unspecified ≤17.0-Classic 2021 Julyenisa_euvdEU
Adobe Acrobat Reader≤ unspecified ≤20.0-Classic 2021 Julyenisa_euvdEU
Adobe Systems Inc. Adobe Acrobat 2017≤ 2017.011.30202 Classic 2017fstec_bduRU
Adobe Systems Inc. Adobe Acrobat 2020≤ 2020.004.30015 Classic 2020fstec_bduRU
Adobe Systems Inc. Adobe Acrobat Document Cloud≤ 2021.007.20091Continuousfstec_bduRU
Adobe Systems Inc. Adobe Acrobat Reader 2017≤ 2017.011.30202 Classic 2017fstec_bduRU
Adobe Systems Inc. Adobe Acrobat Reader 2020≤ 2020.004.30015 Classic 2020fstec_bduRU
Adobe Systems Inc. Adobe Acrobat Reader Document Cloud≤ 2021.007.20091Continuousfstec_bduRU
adobe acrobat17.011.30059 → 17.011.30199nvdUScpe:2.3:a:adobe:acrobat:*:*:*:*:*:*:*:*
adobe acrobat20.001.30005 → 20.004.30006nvdUScpe:2.3:a:adobe:acrobat:*:*:*:*:*:*:*:*
adobe acrobat dc15.008.20082 → 21.005.20058nvdUScpe:2.3:a:adobe:acrobat_dc:*:*:*:*:*:*:*:*
adobe acrobat dc15.008.20082 → 21.005.20060nvdUScpe:2.3:a:adobe:acrobat_dc:*:*:*:*:*:*:*:*
adobe acrobat reader17.011.30059 → 17.011.30199nvdUScpe:2.3:a:adobe:acrobat_reader:*:*:*:*:*:*:*:*
adobe acrobat reader20.001.30005 → 20.004.30006nvdUScpe:2.3:a:adobe:acrobat_reader:*:*:*:*:*:*:*:*
adobe acrobat reader dc15.008.20082 → 21.005.20058nvdUScpe:2.3:a:adobe:acrobat_reader_dc:*:*:*:*:*:*:*:*
adobe acrobat reader dc15.008.20082 → 21.005.20060nvdUScpe:2.3:a:adobe:acrobat_reader_dc:*:*:*:*:*:*:*:*

also known as (4)

Other names and identifiers for this entity.

sources

Which sources assert this record, and when.

cnnvd enisa_euvd fstec_bdu nvd NVD CVE.org MITRE

published 2021-09-29modified 2026-06-17

references (8)

External citations — patches, advisories, analysis.

scry

Attackers weaponise vulnerabilities like this against internet-exposed services. See what is exposed on your perimeter with a free passive scan.

Free scan