Improper revalidation of permissions in Nextcloud Server prior to 14.0.0, 13.0.6 and 12.0.11 lead to not accepting access restrictions by a…

published 2018-10-30 8 y ago modified 2026-06-17 4 mo ago also EUVD-2018-8302

cvss: 8.1; version 3.0, NVD
cisa kev: Not listed; not in CISA's catalog
epss: 1.0%; EPSS 1.0% chance of exploitation in 30 days, percentile 61%
public exploits: 0; none known

Improper revalidation of permissions in Nextcloud Server prior to 14.0.0, 13.0.6 and 12.0.11 lead to not accepting access restrictions by acess tokens.

Patch / fix

fixed in 1

nextcloud nextcloud_server 12.0.11, 13.0.6

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-2018-16466 updated 2025-11-21 cvss 6.4

nextcloud: Improper validation of permissions

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

0.96% chance of exploitation in the next 30 days, higher than 61% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
NVD	3.0	8.1	CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
NVD	2.0	5.5	AV:N/AC:L/Au:S/C:P/I:P/A:N

Affected products

n/a Nextcloud Server

Classification

Weakness

CWE-284 Improper Access Control
CWE-273 Improper Check for Dropped Privileges

References

nextcloud.com /security/advisory/?id=NC-SA-2018-010
vendor-advisory
hackerone.com /reports/388515
third-party-advisory

Sources

CVE List CVE-2018-16466
NVD CVE-2018-16466

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