Auth bypass in Nextcloud Security-Advisories

CVE-2026-45153

Nextcloud is an open source content collaboration platform. From version 33.0.0 to before version 33.1.0, after unlocking a locked Android phone the back-button could be used to bypass the Nextcloud Files app PIN. This issue has been patched in version 33.1.0.

Vulnerability class: Broken Authentication

Published · last modified .

CVSS v3 metric

CVSS v3 base score 4.6 (Medium). Vector: CVSS:3.1/AV:P/AC:H/PR:L/UI:N/S:U/C:H/I:L/A:N.

EPSS exploit prediction

EPSS: 0.002 (9.4th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 9th percentile — 9.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-45153: held from 0.002 to 0.002.

EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: +0.001

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-45153?
CVE-2026-45153 is a medium-severity vulnerability in Nextcloud Security-Advisories, classified under Improper Authentication. CVSS score: 4.6/10. Published 2026-06-01.
How severe is CVE-2026-45153?
Medium severity. CVSS v3 base score is 4.6 out of 10.