Improper Input Validation in Nextcloud Server 15.0.7 allows group admins to create users with IDs of system folders.

published 2020-02-04 6 y ago modified 2026-06-17 4 mo ago also EUVD-2019-6581

cvss: 4.9; version 3.1, NVD
cisa kev: Not listed; not in CISA's catalog
epss: 1.5%; EPSS 1.5% chance of exploitation in 30 days, percentile 73%
public exploits: 0; none known

Patch / fix

fixed in 1 distros 1

nextcloud nextcloud_server 14.0.11, 15.0.8

nextcloud Package Hub 15 SP1 15.0.14-bp151.3.6.1
nextcloud Package Hub 15 SP1, Package Hub 15, Package Hub 12 +1 more 15.0.14-bp151.3.3.1

opensuse advisories openSUSE-SU-2020:0229-1 openSUSE-SU-2020:0220-1

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2019-15624 updated 2025-11-21

nextcloud: Several CVEs fixed in nextcloud 15, 16 and 17

Red Hat All currently supported Red Hat products
not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

1.47% chance of exploitation in the next 30 days, higher than 73% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

hackerone.com https://hackerone.com/reports/508493 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by	version	score	vector
NVD	3.1	4.9	CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:H/A:N
NVD	2.0	4.0	AV:N/AC:L/Au:S/C:N/I:P/A:N

Affected products

n/a Nextcloud Server

Classification

Weakness

CWE-20 Improper Input Validation

References

hackerone.com /reports/508493
exploit, third-party-advisory
lists.opensuse.org /opensuse-security-announce/2020-02/msg00019.html
vendor-advisory, mailing-list, third-party-advisory
lists.opensuse.org /opensuse-security-announce/2020-02/msg00022.html
vendor-advisory, mailing-list, third-party-advisory
nextcloud.com /security/advisory/?id=NC-SA-2019-015
vendor-advisory

Sources

CVE List CVE-2019-15624
NVD CVE-2019-15624

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary