What is CVE-2018-18568?

CVE-2018-18568 is a medium-severity vulnerability in Polycom Unified Communications Software, classified under Improper Certificate Validation. CVSS score: 5.9/10. Published 2018-10-24.

How severe is CVE-2018-18568?

Medium severity. CVSS v3 base score is 5.9 out of 10.

Vulnerability in Polycom Unified Communications Software

CVE-2018-18568

Polycom VVX 500 and 601 devices 5.8.0.12848 and earlier allows man-in-the-middle attackers to obtain sensitive credential information by leveraging failure to validate X.509 certificates when used with an on-premise installation with Skype for Business.

Vulnerability class: Improper Certificate Validation

Published 2018-10-24 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 5.9 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N.

EPSS exploit prediction

EPSS: 0.007 (52.6th percentile), scored 2026-09-29.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 53rd percentile — 52.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.007 · newest: 0.007 · change: 0.000

Affected products

Weakness classification (CWE)

CWE-295 — Improper Certificate Validation

References

www.syss.de/fileadmin/dokumente/Publikationen/Advisories/SYSS-2018-027.txt (Exploit, Third Party Advisory)
seclists.org/bugtraq/2018/Oct/36 (mailing-list, Exploit, Mailing List, Third Party Advisory)

Frequently asked questions

What is CVE-2018-18568?: CVE-2018-18568 is a medium-severity vulnerability in Polycom Unified Communications Software, classified under Improper Certificate Validation. CVSS score: 5.9/10. Published 2018-10-24.
How severe is CVE-2018-18568?: Medium severity. CVSS v3 base score is 5.9 out of 10.