What is CVE-2019-5455?

CVE-2019-5455 is a medium-severity vulnerability in Nextcloud Com.nextcloud.client, classified under Authentication Bypass Using an Alternate Path or Channel. CVSS score: 6.8/10. Published 2019-07-30.

How severe is CVE-2019-5455?

Medium severity. CVSS v3 base score is 6.8 out of 10.

Auth bypass in Nextcloud Com.nextcloud.client

CVE-2019-5455

Bypassing lock protection exists in Nextcloud Android app 3.6.0 when creating a multi-account and aborting the process.

Published 2019-07-30 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 6.8 (Medium). Vector: CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.005 (37.7th percentile), scored 2026-09-30.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 38th percentile — 37.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.005 · newest: 0.005 · change: 0.000

Affected products

Nextcloud Com.nextcloud.client — versions 3.6.1
Nextcloud — versions 3.6.0

Weakness classification (CWE)

References

hackerone.com/reports/490946 (Exploit, Third Party Advisory)

Frequently asked questions

What is CVE-2019-5455?: CVE-2019-5455 is a medium-severity vulnerability in Nextcloud Com.nextcloud.client, classified under Authentication Bypass Using an Alternate Path or Channel. CVSS score: 6.8/10. Published 2019-07-30.
How severe is CVE-2019-5455?: Medium severity. CVSS v3 base score is 6.8 out of 10.