Risk Letters

Exploited vulnerability

CVE-2023-49105

TLP:CLEAR

ownCloud Improper Authentication Vulnerability

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.

Facts

  • Vendor: ownCloud
  • Product: ownCloud
  • CVSS: 9.8
  • EPSS (probability of exploitation within 30 days): 43.2 %
  • On CISA's Known Exploited Vulnerabilities list since: 27 August 2026
  • First known exploitation: 27 August 2026
  • CISA's deadline for US federal agencies: 30 August 2026
  • Weakness: CWE-287
  • First seen by Risk Letters: 27 August 2026

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Data: NVD (public domain), CISA KEV, FIRST EPSS, MITRE ATT&CK, AlienVault OTX. NVD