What is CVE-2018-20809?

CVE-2018-20809 is a high-severity vulnerability in Ivanti Connect Secure, classified under Improper Input Validation. CVSS score: 7.5/10. Published 2019-06-28.

How severe is CVE-2018-20809?

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

Improper input validation in Ivanti Connect Secure

CVE-2018-20809

A crafted message can cause the web server to crash with Pulse Secure Pulse Connect Secure (PCS) 8.3RX before 8.3R5 and Pulse Policy Secure 5.4RX before 5.4R5. This is not applicable to PCS 8.1RX.

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

Published 2019-06-28 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.027 (85.5th percentile), scored 2026-09-30.

Low probability of exploitation in the next 30 days, but still tracked. 86th percentile — 85.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.027 · newest: 0.027 · change: 0.000

Affected products

Ivanti Connect Secure — versions 8.3
Pulsesecure Pulse Policy Secure — versions 4.4, 5.0, 5.1

Weakness classification (CWE)

CWE-20 — Improper Input Validation

References

kb.pulsesecure.net/articles/Pulse_Security_Advisories/SA43877/ (Vendor Advisory)

Frequently asked questions

What is CVE-2018-20809?: CVE-2018-20809 is a high-severity vulnerability in Ivanti Connect Secure, classified under Improper Input Validation. CVSS score: 7.5/10. Published 2019-06-28.
How severe is CVE-2018-20809?: High severity. CVSS v3 base score is 7.5 out of 10.