What is CVE-2023-28646?

CVE-2023-28646 is a medium-severity vulnerability in Nextcloud, classified under Improper Preservation of Permissions. CVSS score: 4.4/10. Published 2023-03-30.

How severe is CVE-2023-28646?

Medium severity. CVSS v3 base score is 4.4 out of 10.

Auth bypass in Nextcloud

CVE-2023-28646

Nextcloud android is an android app for interfacing with the nextcloud home server ecosystem. In versions from 3.7.0 and before 3.24.1 an attacker that has access to the unlocked physical device can bypass the Nextcloud Android Pin/passcode protection via a thirdparty app. This allows to see meta information like sharer, sharees and activity of files. It is recommended that the Nextcloud Android app is upgraded to 3.24.1. There are no known workarounds for this vulnerability.

Published 2023-03-30 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 4.4 (Medium). Vector: CVSS:3.1/AV:P/AC:H/PR:L/UI:R/S:C/C:L/I:L/A:L.

EPSS exploit prediction

EPSS: 0.002 (12.3th percentile), scored 2026-09-29.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 12th percentile — 12.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: 0.000

Affected products

Nextcloud
Nextcloud Security-Advisories — versions >= 3.7.0, < 3.24.1

Weakness classification (CWE)

References

github.com/nextcloud/security-advisories/security/advisories/GHSA-c3rf-94h6-vj8v (Vendor Advisory)
github.com/nextcloud/android/pull/11242 (Patch, Issue Tracking)

Frequently asked questions

What is CVE-2023-28646?: CVE-2023-28646 is a medium-severity vulnerability in Nextcloud, classified under Improper Preservation of Permissions. CVSS score: 4.4/10. Published 2023-03-30.
How severe is CVE-2023-28646?: Medium severity. CVSS v3 base score is 4.4 out of 10.