What is CVE-2021-26605?

CVE-2021-26605 is a high-severity vulnerability in Microsoft Windows, classified under Improper Input Validation. CVSS score: 7.5/10. Published 2021-08-05.

How severe is CVE-2021-26605?

High severity. CVSS v3 base score is 7.5 out of 10.

Improper input validation in Microsoft Windows

CVE-2021-26605

An improper input validation vulnerability in the service of ezPDFReader allows attacker to execute arbitrary command. This issue occurred when the ezPDF launcher received and executed crafted input values through JSON-RPC communication.

Vulnerability class: Drupalgeddon 2 (CVE-2018-7600)

Published 2021-08-05 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N.

EPSS exploit prediction

EPSS: 0.010 (63.1th percentile), scored 2026-10-07.

Low probability of exploitation in the next 30 days, but still tracked. 63rd percentile — 63.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.010 · newest: 0.010 · change: 0.000

Affected products

Microsoft Windows
Unidocs Ezpdfreader — versions 2.0 ~ 3.0

Weakness classification (CWE)

CWE-20 — Improper Input Validation

References

www.boho.or.kr/krcert/secNoticeView.do (Third Party Advisory)

Frequently asked questions

What is CVE-2021-26605?: CVE-2021-26605 is a high-severity vulnerability in Microsoft Windows, classified under Improper Input Validation. CVSS score: 7.5/10. Published 2021-08-05.
How severe is CVE-2021-26605?: High severity. CVSS v3 base score is 7.5 out of 10.