What is CVE-2018-6320?

CVE-2018-6320 is a critical-severity vulnerability in Ivanti Connect Secure, classified under Improper Input Validation. CVSS score: 9.8/10. Published 2018-09-06.

How severe is CVE-2018-6320?

Critical severity. CVSS v3 base score is 9.8 out of 10.

Improper input validation in Ivanti Connect Secure

CVE-2018-6320

A vulnerability has been discovered in login.cgi in Pulse Secure Pulse Connect Secure (PCS) 8.1RX before 8.1R12 and 8.3RX before 8.3R2 and Pulse Policy Secure (PPS) 5.2RX before 5.2R9 and 5.4RX before 5.4R2 wherein an http(s) Host header received from the browser is trusted without validation.

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

Published 2018-09-06 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.041 (90.4th percentile), scored 2026-09-29.

Low probability of exploitation in the next 30 days, but still tracked. 90th percentile — 90.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.041 · newest: 0.041 · change: 0.000

Affected products

Ivanti Connect Secure — versions 8.1
Pulsesecure Pulse Connect Secure — versions 8.1r1.0, 8.1rx, 8.3rx
Pulsesecure Pulse Policy Secure — versions 5.2r1.0, 5.2r2.0, 5.2r3.0

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-2018-6320?: CVE-2018-6320 is a critical-severity vulnerability in Ivanti Connect Secure, classified under Improper Input Validation. CVSS score: 9.8/10. Published 2018-09-06.
How severe is CVE-2018-6320?: Critical severity. CVSS v3 base score is 9.8 out of 10.