What is CVE-2018-18659?

CVE-2018-18659 is a high-severity vulnerability in Arcserve Udp, classified under Improper Restriction of XML External Entity Reference (XXE). CVSS score: 7.5/10. Published 2018-10-26.

How severe is CVE-2018-18659?

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

XXE in Arcserve Udp

CVE-2018-18659

An issue was discovered in Arcserve Unified Data Protection (UDP) through 6.5 Update 4. There is a DDI-VRT-2018-19 Unauthenticated XXE in /management/UdpHttpService issue.

Vulnerability class: XXE (XML External Entity)

Published 2018-10-26 · 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:H/I:N/A:N.

EPSS exploit prediction

EPSS: 0.018 (78.0th percentile), scored 2026-09-30.

Low probability of exploitation in the next 30 days, but still tracked. 78th percentile — 78.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.018 · newest: 0.018 · change: 0.000

Affected products

Arcserve Udp — versions 6.0, 6.5

Weakness classification (CWE)

CWE-611 — Improper Restriction of XML External Entity Reference (XXE)

References

support.arcserve.com/s/article/360001392563 (Patch, Vendor Advisory)
www.digitaldefense.com/blog/zero-day-alerts/arcserve-disclosure/ (Third Party Advisory)
support.arcserve.com/s/article/Security-vulnerabilities-with-Arcserve-UDP-and-f… (Patch, Vendor Advisory)
exchange.xforce.ibmcloud.com/vulnerabilities/152033 (Third Party Advisory)

Frequently asked questions

What is CVE-2018-18659?: CVE-2018-18659 is a high-severity vulnerability in Arcserve Udp, classified under Improper Restriction of XML External Entity Reference (XXE). CVSS score: 7.5/10. Published 2018-10-26.
How severe is CVE-2018-18659?: High severity. CVSS v3 base score is 7.5 out of 10.