What is CVE-2020-8181?

CVE-2020-8181 is a medium-severity vulnerability in Nextcloud Contacts, classified under CWE-840. CVSS score: 4.3/10. Published 2020-07-10.

How severe is CVE-2020-8181?

Medium severity. CVSS v3 base score is 4.3 out of 10.

Arbitrary file upload in Nextcloud Contacts

CVE-2020-8181

A missing file type check in Nextcloud Contacts 3.2.0 allowed a malicious user to upload any file as avatars.

Published 2020-07-10 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 4.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N.

EPSS exploit prediction

EPSS: 0.008 (54.5th percentile), scored 2026-09-29.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 55th percentile — 54.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.008 · newest: 0.008 · change: 0.000

Affected products

Nextcloud Contacts
Nextcloud Contact — versions 3.3.0

Weakness classification (CWE)

References

hackerone.com/reports/808287,
nextcloud.com/security/advisory/ (Vendor Advisory)

Frequently asked questions

What is CVE-2020-8181?: CVE-2020-8181 is a medium-severity vulnerability in Nextcloud Contacts, classified under CWE-840. CVSS score: 4.3/10. Published 2020-07-10.
How severe is CVE-2020-8181?: Medium severity. CVSS v3 base score is 4.3 out of 10.