ACTIVELY EXPLOITED

CVE-2023-49105: ownCloud Improper Authentication Vulnerability

Facts
VendorownCloud
ProductownCloud
Actively exploitedYes
Added to CISA KEV27 Aug 2026
CISA federal deadline30 Aug 2026
Weakness (CWE)CWE-287

Required action (CISA's text)

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.

Description (NVD)

ownCloud contains an improper authentication vulnerability that allows an attacker to access, modify, or delete any file without authentication if the username of a victim is known, and the victim has no signing-key configured.

SOURCES

Other ownCloud flaws

Data from NVD, CISA KEV, FIRST EPSS and vendor advisories. Updated 10 Nov 2026.