How severe is CVE-2023-49105?

CVE-2023-49105 has a CVSS 3.1 base score of 9.8 (CRITICAL). EPSS estimates a 42.9% probability of exploitation in the next 30 days. It is listed in the CISA Known Exploited Vulnerabilities catalog.

CVE-2023-49105: ownCloud Improper Authentication Vulnerability

CISA Known Exploited Vulnerabilities

ownCloud Improper Authentication Vulnerability is confirmed as actively exploited and is listed in the CISA KEV catalog.

Added to KEV

2026-08-27

Remediation due

2026-08-30

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.

CISA notes
https://owncloud.org/security ; https://owncloud.com/security-advisories/webdav-api-authentication-bypass-using-pre-signed-urls/ ; BOD 26-04: https://www.cisa.gov/news-events/directives/bod-26-04-prioritizing-security-updates-based-risk ; Forensics Triage Requirements: https://www.cisa.gov/news-events/directives/bod-26-04-implementation-guidance-prioritizing-security-updates-based-risk ; https://nvd.nist.gov/vuln/detail/CVE-2023-49105

Description

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.

Severity

CVSS 3.1 · CNA9.8 CRITICAL

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

SSVC · CISA-ADP

Exploitationactive

Automatableyes

Technical impacttotal

Exploitation Context

as of October 14, 2026

All KEV statistics→

CISA added CVE-2023-49105 to the KEV catalog 1,010 days after its CVE record was published. The median for entries added in 2026 so far is 15 days.
It is one of 2 ownCloud entries in the CISA KEV catalog, and the only one added in 2026.
Its current EPSS score (42.9%) is higher than that of 47% of CISA KEV entries.

Affected Products

Vendor	Product	Affected versions
-	-	n/a

References

2 Links

Other references

Record Details

Published

2023-11-21

Last updated

2026-08-28

Assigner (CNA)

mitre

Credited to

CVE record data © The MITRE Corporation, used under the CVE Terms of Use. Exploited-in-the-wild data from the CISA Known Exploited Vulnerabilities catalog (CC0). Exploit prediction scores by FIRST EPSS (first.org/epss). This site is not endorsed or certified by MITRE, NVD, CISA, or FIRST.