What is CVE-2026-68493?

CVE-2026-68493 is a low-severity vulnerability in Nextcloud Server, classified under Authorization Bypass Through User-Controlled Key. CVSS score: 3.1/10. Published 2026-09-18.

How severe is CVE-2026-68493?

Low severity. CVSS v3 base score is 3.1 out of 10.

Auth bypass in Nextcloud Server

CVE-2026-68493

After guessing a 62^15 complex unique identifier, a malicious logged in user was able to retrieve a list of memberships for a circle they are not a member of.

Vulnerability class: IDOR (Insecure Direct Object Reference)

CVSS v3 metric

CVSS v3 base score 3.1 (Low). Vector: CVSS:3.0/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N.

Affected products

Nextcloud Server

Weakness classification (CWE)

CWE-639 — Authorization Bypass Through User-Controlled Key

References

support@hackerone.com

Frequently asked questions

What is CVE-2026-68493?: CVE-2026-68493 is a low-severity vulnerability in Nextcloud Server, classified under Authorization Bypass Through User-Controlled Key. CVSS score: 3.1/10. Published 2026-09-18.
How severe is CVE-2026-68493?: Low severity. CVSS v3 base score is 3.1 out of 10.