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CVE-2021-39858

16
FAUCET Score

CVE-2021-39858 is an out-of-bounds read vulnerability affecting Adobe Acrobat Reader DC versions 2021.005.20060 and earlier, 2020.004.30006 and earlier, and 2017.011.30199 and earlier, across Adobe, Apple, and Microsoft platforms. This low-severity vulnerability (CVSS 3.3) requires user interaction, specifically opening a malicious file, and could lead to the disclosure of arbitrary memory information in the context of the current user. There is no evidence of active exploitation, no known public exploit code (Metasploit, Nuclei, ExploitDB), and it is not listed in CISA's KEV catalog. Despite low EPSS and FAUCET scores, it has received some community discussion and media coverage.

Impacted Technologies

VendorProductVersion(s)CPE
>= 20.006.20034, <= 21.005.20060CPE matchmatch criteria
cpe:2.3:a:adobe:acrobat_dc:*:*:*:*:continuous:*:*:*
>= 20.006.20034, <= 21.005.20058CPE matchmatch criteria
cpe:2.3:a:adobe:acrobat_dc:*:*:*:*:continuous:*:*:*
>= 20.006.20034, <= 21.005.20060CPE matchmatch criteria
cpe:2.3:a:adobe:acrobat_reader_dc:*:*:*:*:continuous:*:*:*
>= 17.011.30158, <= 17.011.30199CPE matchmatch criteria
cpe:2.3:a:adobe:acrobat_2017:*:*:*:*:classic_2017:*:*:*
>= 17.011.30158, <= 17.011.30199CPE matchmatch criteria
cpe:2.3:a:adobe:acrobat_reader_2017:*:*:*:*:classic_2017:*:*:*

CVSS Data

CVSS version used by this source: 3.0

3.3LOW

CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N

Attack Vector
LOCAL
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
REQUIRED
Scope
UNCHANGED
Confidentiality Impact
LOW
Integrity Impact
NONE
Availability Impact
NONE
Exploitability Score
1.8
Impact Score
1.4
CvssVersion
3.0

Exploit Intelligence

EPSS Score
2.46%
Probability of exploitation in next 30 days
EPSS Percentile
82.8%
Percentile rank of EPSS score among Peer Group
As of 2026-07-27
Model: v2026.06.15
This CVE's current EPSS score of 0.0246 is in the 93rd percentile among its peer group of 577 CVEs.

Social Chatter

The average CVE in this peer group has 0.0 Twitter, 0.0 Reddit, 0.1 Bluesky, 0.0 Mastodon, and 0.0 GitHub mentions.

Media Mentions

The average CVE in this peer group has 0.1 InfoSec Media, 0.0 Vendor Blog, and 0.0 Security Researcher mentions.

Remediation

Vendor Patches (1)

adobevendor investigatingvia nvd_reference
View patch

References

helpx.adobe.com / security/products/acrobat/apsb21-55.html
Release NotesVendor Advisory