What is CVE-2020-8121?

CVE-2020-8121 is a high-severity vulnerability in Nextcloud Server, classified under Improper Access Control. CVSS score: 8.1/10. Published 2020-02-04.

How severe is CVE-2020-8121?

High severity. CVSS v3 base score is 8.1 out of 10.

Vulnerability in Nextcloud Server

CVE-2020-8121

A bug in Nextcloud Server 14.0.4 could expose more data in reshared link shares than intended by the sharer.

Published 2020-02-04 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 8.1 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N.

EPSS exploit prediction

EPSS: 0.010 (63.3th percentile), scored 2026-10-19.

Low probability of exploitation in the next 30 days, but still tracked. 63rd percentile — 63.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.010 · newest: 0.010 · change: 0.000

Affected products

Nextcloud Server
Nextcloud Server — versions 14.0.4

Weakness classification (CWE)

References

hackerone.com/reports/452854 (Exploit, Third Party Advisory)
nextcloud.com/security/advisory/ (Vendor Advisory)

Frequently asked questions

What is CVE-2020-8121?: CVE-2020-8121 is a high-severity vulnerability in Nextcloud Server, classified under Improper Access Control. CVSS score: 8.1/10. Published 2020-02-04.
How severe is CVE-2020-8121?: High severity. CVSS v3 base score is 8.1 out of 10.