What is CVE-2023-48303?

CVE-2023-48303 is a low-severity vulnerability in Nextcloud Server, classified under Improper Access Control. CVSS score: 2.4/10. Published 2023-11-21.

How severe is CVE-2023-48303?

Low severity. CVSS v3 base score is 2.4 out of 10.

Vulnerability in Nextcloud Server

CVE-2023-48303

Nextcloud Server provides data storage for Nextcloud, an open source cloud platform. Starting in version 25.0.0 and prior to versions 25.0.11, 26.0.6, and 27.1.0 of Nextcloud Server and Nextcloud Enterprise Server, admins can change authentication details of user configured external storage. Nextcloud Server and Nextcloud Enterprise Server versions 25.0.11, 26.0.6, and 27.1.0 contain a patch for this issue. No known workarounds are available.

Published 2023-11-21 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 2.4 (Low). Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:N/I:N/A:L.

EPSS exploit prediction

EPSS: 0.007 (50.1th percentile), scored 2026-09-30.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 50th percentile — 50.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.007 · newest: 0.007 · change: 0.000

Affected products

Nextcloud Server
Nextcloud Security-Advisories — versions >= 25.0.0, < 25.0.11, >= 26.0.0, < 26.0.6, >= 27.0.0, < 27.1.0

Weakness classification (CWE)

CWE-284 — Improper Access Control

References

github.com/nextcloud/security-advisories/security/advisories/GHSA-2448-44rp-c7hh (Vendor Advisory)
github.com/nextcloud/server/pull/39895 (Patch, Issue Tracking)
hackerone.com/reports/2107934 (Permissions Required)

Frequently asked questions

What is CVE-2023-48303?: CVE-2023-48303 is a low-severity vulnerability in Nextcloud Server, classified under Improper Access Control. CVSS score: 2.4/10. Published 2023-11-21.
How severe is CVE-2023-48303?: Low severity. CVSS v3 base score is 2.4 out of 10.