What is CVE-2021-22895?

CVE-2021-22895 is a medium-severity vulnerability in Nextcloud Desktop, classified under Improper Certificate Validation. CVSS score: 5.9/10. Published 2021-06-11.

How severe is CVE-2021-22895?

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

Vulnerability in Nextcloud Desktop

CVE-2021-22895

Nextcloud Desktop Client before 3.3.1 is vulnerable to improper certificate validation due to lack of SSL certificate verification when using the "Register with a Provider" flow.

Vulnerability class: Improper Certificate Validation

Published 2021-06-11 · 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:N/I:H/A:N.

EPSS exploit prediction

EPSS: 0.010 (62.3th percentile), scored 2026-09-29.

Low probability of exploitation in the next 30 days, but still tracked. 62nd percentile — 62.3% 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 Desktop
Debian Linux — versions 10.0, 11.0
Nextcloud Desktop Client — versions Fixed in 3.3.1

Weakness classification (CWE)

CWE-295 — Improper Certificate Validation

References

hackerone.com/reports/903424 (Exploit, Third Party Advisory, Issue Tracking)
github.com/nextcloud/desktop/pull/2926 (Patch, Third Party Advisory)
github.com/nextcloud/desktop/releases/tag/v3.1.3 (Third Party Advisory, Release Notes)
github.com/nextcloud/security-advisories/security/advisories/GHSA-qpgp-vf4p-wcw5 (Third Party Advisory)
www.debian.org/security/2021/dsa-4974 (vendor-advisory, Third Party Advisory)

Frequently asked questions

What is CVE-2021-22895?: CVE-2021-22895 is a medium-severity vulnerability in Nextcloud Desktop, classified under Improper Certificate Validation. CVSS score: 5.9/10. Published 2021-06-11.
How severe is CVE-2021-22895?: Medium severity. CVSS v3 base score is 5.9 out of 10.