What is CVE-2021-39826?

CVE-2021-39826 is a high-severity vulnerability in Adobe Digital Editions, classified under OS Command Injection. CVSS score: 8.6/10. Published 2021-09-27.

How severe is CVE-2021-39826?

High severity. CVSS v3 base score is 8.6 out of 10.

RCE in Adobe Digital Editions

CVE-2021-39826

Adobe Digital Editions 4.5.11.187646 (and earlier) are affected by an arbitrary command execution vulnerability. An authenticated attacker could leverage this vulnerability to execute arbitrary commands. User interaction is required to abuse this vulnerability in that a user must open a maliciously crafted .epub file.

Vulnerability class: Command Injection (OS Command Injection)

Published 2021-09-27 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 8.6 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.021 (80.7th percentile), scored 2026-10-02.

Low probability of exploitation in the next 30 days, but still tracked. 81st percentile — 80.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.021 · newest: 0.021 · change: 0.000

Affected products

Adobe Digital Editions — versions unspecified
Adobe Digital Editions
Apple macOS

Weakness classification (CWE)

CWE-78 — OS Command Injection

References

helpx.adobe.com/security/products/Digital-Editions/apsb21-80.html (Patch, Vendor Advisory)

Frequently asked questions

What is CVE-2021-39826?: CVE-2021-39826 is a high-severity vulnerability in Adobe Digital Editions, classified under OS Command Injection. CVSS score: 8.6/10. Published 2021-09-27.
How severe is CVE-2021-39826?: High severity. CVSS v3 base score is 8.6 out of 10.