What is CVE-2021-32653?

CVE-2021-32653 is a low-severity vulnerability in Nextcloud Server, classified under Insertion of Sensitive Information into Sent Data. CVSS score: 2.7/10. Published 2021-06-01.

How severe is CVE-2021-32653?

Low severity. CVSS v3 base score is 2.7 out of 10.

Vulnerability in Nextcloud Server

CVE-2021-32653

Nextcloud Server is a Nextcloud package that handles data storage. Nextcloud Server versions prior to 19.0.11, 20.0.10, or 21.0.2 send user IDs to the lookup server even if the user has no fields set to published. The vulnerability is patched in versions 19.0.11, 20.0.10, and 21.0.2; no workarounds outside the updates are known to exist.

Published 2021-06-01 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 2.7 (Low). Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:L/I:N/A:N.

EPSS exploit prediction

EPSS: 0.012 (67.1th percentile), scored 2026-09-29.

Low probability of exploitation in the next 30 days, but still tracked. 67th percentile — 67.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.012 · newest: 0.012 · change: 0.000

Affected products

Nextcloud Server
Nextcloud Security-Advisories — versions < 19.0.11, >= 20.0.0, < 20.0.10, >= 21.0.0, < 21.0.2

Weakness classification (CWE)

CWE-201 — Insertion of Sensitive Information into Sent Data

References

github.com/nextcloud/security-advisories/security/advisories/GHSA-396j-vqpr-qg45 (Third Party Advisory)
hackerone.com/reports/1173436 (Permissions Required, Third Party Advisory)
security.gentoo.org/glsa/202208-17 (vendor-advisory, Third Party Advisory)

Frequently asked questions

What is CVE-2021-32653?: CVE-2021-32653 is a low-severity vulnerability in Nextcloud Server, classified under Insertion of Sensitive Information into Sent Data. CVSS score: 2.7/10. Published 2021-06-01.
How severe is CVE-2021-32653?: Low severity. CVSS v3 base score is 2.7 out of 10.