What is CVE-2026-77173?

CVE-2026-77173 is a medium-severity vulnerability in Nextcloud Files Confidential, classified under Improper Access Control. CVSS score: 4.3/10. Published 2026-10-27.

How severe is CVE-2026-77173?

Medium severity. CVSS v3 base score is 4.3 out of 10.

Vulnerability in Nextcloud Files Confidential

CVE-2026-77173

A user could create a docx or odt file with a # in the filename with confidential information such as a credit card number and have it not be marked as confidential.

Published 2026-10-27.

CVSS v3 metric

CVSS v3 base score 4.3 (Medium). Vector: CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N.

EPSS exploit prediction

No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.

Affected products

Nextcloud Files Confidential

Weakness classification (CWE)

CWE-284 — Improper Access Control

References

hackerone.com/reports/3682163

Frequently asked questions

What is CVE-2026-77173?: CVE-2026-77173 is a medium-severity vulnerability in Nextcloud Files Confidential, classified under Improper Access Control. CVSS score: 4.3/10. Published 2026-10-27.
How severe is CVE-2026-77173?: Medium severity. CVSS v3 base score is 4.3 out of 10.