CVE-2021-28550

Acrobat Reader DC versions versions 2021.001.20150 (and earlier), 2020.001.30020 (and earlier) and 2017.011.30194 (and earlier) are affected by a…

Browse: All 2021 CVEs · All vendors

CVSS score: 8.8 High
CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
CISA KEV: Yes — actively exploited (added 2021-11-03, remediation due 2021-11-17)
Weakness (CWE): CWE-416
Published: 2021-09-02
Last modified: 2026-06-17
NVD status: Analyzed

Description

Acrobat Reader DC versions versions 2021.001.20150 (and earlier), 2020.001.30020 (and earlier) and 2017.011.30194 (and earlier) are affected by a Use After Free vulnerability. An unauthenticated attacker could leverage this vulnerability to achieve arbitrary code execution in the context of the current user. Exploitation of this issue requires user interaction in that a victim must open a malicious file.

Affected products

adobe acrobat dc
adobe acrobat reader dc
adobe acrobat
adobe acrobat reader

Affected ranges per NVD CPE data; confirm exact versions in the vendor advisory.

Required action (CISA)

Apply updates per vendor instructions. Federal remediation deadline: 2021-11-17.

How to prioritize this

This vulnerability is on the CISA KEV list, meaning it is being actively exploited — treat it as urgent regardless of the raw CVSS number. Use the live CVE lookup for the latest NVD data, and the CVSS 3.1 calculator to model your own environmental score. For the actively exploited vulnerabilities that matter this week, read The Exploit HQ daily security brief.

References

FAQ

Is CVE-2021-28550 actively exploited?

Yes. CISA added CVE-2021-28550 to its Known Exploited Vulnerabilities (KEV) catalog on 2021-11-03, with a federal remediation deadline of 2021-11-17. A KEV listing means real-world exploitation is confirmed, so patching this should be prioritized above many higher-CVSS bugs that aren't being exploited.

What is the CVSS score of CVE-2021-28550?

CVE-2021-28550 has a CVSS base score of 8.8 (High). Its vector string is CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H.

Related vulnerabilities

Data source: NVD & CISA KEV. Shown as-is; nothing added. Last generated from NVD data — re-check the live tool for updates.