CVE-2023-49105: Owncloud Server

What is CVE-2023-49105?

An issue was discovered in ownCloud owncloud/core before 10.13.1. An attacker can access, modify, or delete any file without authentication if the username of a victim is known, and the victim has no signing-key configured. This occurs because pre-signed URLs can be accepted even when no signing-key is configured for the owner of the files. The earliest affected version is 10.6.0.

CVSS9.8 NVD 3.1

SeverityCRITICAL

Exploitation In the wild In CISA KEV

EPSS11% · P96

Triage statusActive Exploit

ActionPatch immediately

CVSS vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CWECWE-287, CWE-287

NVD published2023-11-21

NVD last modified2026-08-27

Timeline

2023-11-21Published to the U.S. National Vulnerability Database (NVD)
2026-08-27Added to the CISA Known Exploited Vulnerabilities (KEV) catalog
2026-08-27NVD record last updated
2026-08-30CISA federal remediation deadline (BOD 22-01)

CISA Known Exploited Vulnerability

ownCloud Improper Authentication Vulnerability

Added to KEV2026-08-27

Federal patch deadline2026-08-30

Known ransomware useUnknown

Affected product

Owncloud Server

Remediation Steps

Apply the vendor security update for ownCloud ownCloud as a priority.
Restrict network exposure of the affected service to trusted sources until patched.
Review logs and detections for indicators of exploitation.
Confirm fixed versions against the official vendor advisory before deploying.

References

Referenced in our briefings & reports

Vulnerability Priority Report – Week 4 of August 2026 (August 24 – 30)

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🤖 This CVE page is generated by defend.network from NVD, CISA KEV, EPSS, and our verified daily briefings. Severity and exploitation data come from official sources; always verify remediation steps against the official vendor advisory before acting in production.