What is CVE-2018-3764?

CVE-2018-3764 is a medium-severity vulnerability in Nextcloud Contacts, classified under Cross-site Scripting. CVSS score: 4.8/10. Published 2018-07-05.

How severe is CVE-2018-3764?

Medium severity. CVSS v3 base score is 4.8 out of 10.

XSS in Nextcloud Contacts

CVE-2018-3764

In Nextcloud Contacts before 2.1.2, a missing sanitization of search results for an autocomplete field could lead to a stored XSS requiring user-interaction. The missing sanitization only affected group names, hence malicious search results could only be crafted by privileged users like admins or group admins.

Vulnerability class: XSS (Cross-Site Scripting)

Published 2018-07-05 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 4.8 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N.

EPSS exploit prediction

EPSS: 0.006 (48.7th percentile), scored 2026-09-29.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 49th percentile — 48.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.006 · newest: 0.006 · change: 0.000

Affected products

Nextcloud Contacts
Nextcloud Contacts Application — versions <2.1.2

Weakness classification (CWE)

CWE-79 — Cross-site Scripting

References

nextcloud.com/security/advisory/ (Vendor Advisory)

Frequently asked questions

What is CVE-2018-3764?: CVE-2018-3764 is a medium-severity vulnerability in Nextcloud Contacts, classified under Cross-site Scripting. CVSS score: 4.8/10. Published 2018-07-05.
How severe is CVE-2018-3764?: Medium severity. CVSS v3 base score is 4.8 out of 10.