CVE-2023-49105

ownCloud Improper Authentication Vulnerability

IN CISA KEV

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.

Vendor: ownCloud
Product: ownCloud
CVSS 3.1: 9.8 (critical), scored by NVD (primary)CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CVSS 3.1: 9.8 (critical), scored by cve@mitre.orgCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CWE: CWE-287
Published: 2023-11-21
NVD modified: 2026-08-28
NVD status: Analyzed

CISA KEV

Date added: 2026-08-27
Due date: 2026-08-30
Ransomware use: Unknown
Required action: Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.

EPSS

42.9% chance of exploitation in the next 30 days (percentile 98th)

FIRST EPSS, updated 17 Oct 2026. About EPSS

CVSS is severity, EPSS is likelihood, KEV means already exploited. EPSS is a statistical probability, not a certainty: a low score does not make a bug safe, and a high one does not prove it is being exploited.

References

owncloud.com (Vendor Advisory)
owncloud.org (Product)
owncloud.com (Vendor Advisory)
owncloud.org (Product)
hunt.io (Third Party Advisory)
www.cisa.gov (US Government Resource)

Data last updated 18 Oct 2026. Sources: NVD API 2.0, CISA KEV catalog, FIRST EPSS. Links: NVD, CISA KEV. Metadata only. ThreatWire does not host exploit code.