How severe is CVE-2021-39846?

CVE-2021-39846 has a CVSS 3.x base score of 6.1, rated medium severity. It is exploitable over local access with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is none, integrity low, and availability high.

Is CVE-2021-39846 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (83rd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-39846?

CVE-2021-39846 primarily affects Adobe Acrobat. In total, 4 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-39846?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2021-39846 published?

CVE-2021-39846 was published on 2021-09-29 and last updated on 2026-06-17.

CVE-2021-39846

CVE-2021-39846 is a medium-severity vulnerability in Adobe Acrobat with a CVSS 3.x base score of 6.1. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-787.

Key facts

Severity: Medium (CVSS 3.x base score 6.1)
CVSS v2: 5.8
EPSS exploit prediction: 3% (83rd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-787
Affected product: Adobe Acrobat
Published: 2021-09-29
Last modified: 2026-06-17

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 stack overflow vulnerability due to insecure handling of a crafted PDF file, potentially resulting in memory corruption in the context of the current user. Exploitation requires user interaction in that a victim must open a crafted PDF file in Acrobat Reader.

Frequently asked questions

What is CVE-2021-39846?: Acrobat Reader DC versions 2021.005.20060 (and earlier), 2020.004.30006 (and earlier) and 2017.011.30199 (and earlier) are affected by a stack overflow vulnerability due to insecure handling of a crafted PDF file, potentially resulting in memory corruption in the context of the current user. Exploitation requires user interaction in that a victim must open a crafted PDF file in Acrobat Reader.
How severe is CVE-2021-39846?: CVE-2021-39846 has a CVSS 3.x base score of 6.1, rated medium severity. It is exploitable over local access with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is none, integrity low, and availability high.
Is CVE-2021-39846 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (83rd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-39846?: CVE-2021-39846 primarily affects Adobe Acrobat. In total, 4 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-39846?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-39846 published?: CVE-2021-39846 was published on 2021-09-29 and last updated on 2026-06-17.

References

https://helpx.adobe.com/security/products/acrobat/apsb21-55.html

Affected products (4)

cpe:2.3:a:adobe:acrobat:*:*:*:*:classic:*:*:*
cpe:2.3:a:adobe:acrobat_reader:*:*:*:*:classic:*:*:*
cpe:2.3:a:adobe:acrobat_dc:*:*:*:*:continuous:*:*:*
cpe:2.3:a:adobe:acrobat_reader_dc:*:*:*:*:continuous:*:*:*

More vulnerabilities in Adobe Acrobat

CVE-2018-4872 — Critical (CVSS 10.0): An issue was discovered in Adobe Acrobat Reader 2018.009.20050 and earlier versions, 2017.011.30070 and earlier…
CVE-2016-1044 — Critical (CVSS 10.0): Adobe Reader and Acrobat before 11.0.16, Acrobat and Acrobat Reader DC Classic before 15.006.30172, and Acrobat and…
CVE-2016-1041 — Critical (CVSS 10.0): Adobe Reader and Acrobat before 11.0.16, Acrobat and Acrobat Reader DC Classic before 15.006.30172, and Acrobat and…
CVE-2016-1038 — Critical (CVSS 10.0): Adobe Reader and Acrobat before 11.0.16, Acrobat and Acrobat Reader DC Classic before 15.006.30172, and Acrobat and…
CVE-2015-7622 — Critical (CVSS 10.0): Adobe Reader and Acrobat 10.x before 10.1.16 and 11.x before 11.0.13, Acrobat and Acrobat Reader DC Classic before…
CVE-2015-6691 — Critical (CVSS 10.0): Use-after-free vulnerability in Adobe Reader and Acrobat 10.x before 10.1.16 and 11.x before 11.0.13, Acrobat and…

All CVEs affecting Adobe Acrobat →

Other CWE-787 (Out-of-bounds Write) vulnerabilities

CVE-2026-42369 — Critical (CVSS 10.0): GV-VMS V20 is a Video Monitoring Software used to gather the feeds of many surveillance cameras and manage other…
CVE-2026-4746 — Critical (CVSS 10.0): Out-of-bounds Write vulnerability in timeplus-io proton (base/poco/Foundation/src‎ modules). This vulnerability is…
CVE-2025-43300 — Critical (CVSS 10.0): An out-of-bounds write issue was addressed with improved bounds checking. This issue is fixed in iOS 15.8.5 and iPadOS…
CVE-2025-24201 — Critical (CVSS 10.0): An out-of-bounds write issue was addressed with improved checks to prevent unauthorized actions. This issue is fixed in…
CVE-2024-42479 — Critical (CVSS 10.0): llama.cpp provides LLM inference in C/C++. The unsafe `data` pointer member in the `rpc_tensor` structure can cause…
CVE-2024-39791 — Critical (CVSS 10.0): Stack-based buffer overflow vulnerabilities affecting Vonets industrial wifi bridge relays and wifi bridge…

Browse all CWE-787 (Out-of-bounds Write) vulnerabilities →