CSIRTS // UNIFIED SECURITY ADVISORY FEEDSYS ● ONLINE · POWERED BY INTELFUSIONS.COM

← Back to feed

CVE-2023-49105: ownCloud Improper Authentication Vulnerability

criticalknown exploitedpublic exploitCVE-2023-49105
Actively exploited. At least one CVE in this advisory is listed in the CISA Known Exploited Vulnerabilities catalog — exploitation has been observed in the wild. Treat remediation as urgent.
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.

CSIRTS triage

vendor: ownCloudproduct: ownCloudAuthentication bypass
What
ownCloud allows unauthenticated attackers to access, modify, or delete any file if the victim username is known and signing-key is not configured.
Who is affected
ownCloud installations where users have not configured signing-keys.
Urgency
Critical; actively exploited vulnerability on CISA's Known Exploited Vulnerabilities catalog.
Action
Apply patches and mandate signing-key configuration for all users immediately.

AI-assisted analysis generated from the source advisory — verify against the original.

⚡ Watch ownCloud

Get an email when a new ownCloud advisory drops — max one per day, one-click unsubscribe.

Details

Source
CISA Known Exploited Vulnerabilities (US · database · site)
Severity
critical
Published
2026-08-27
Exploitation
Observed in the wild (CISA KEV)

Original advisory: https://nvd.nist.gov/vuln/detail/CVE-2023-49105

Exploitation outlook

EPSS (FIRST.org) estimates each CVE’s probability of exploitation in the next 30 days — here is the CSIRTS.com read on those numbers.

Referenced CVEs

CVECSIRTS overviewExternal
CVE-2023-49105coverage & exploitation statusNVD · CVE.org

Same CVEs, other sources

How other CERTs, PSIRTs and databases cover the vulnerabilities in this advisory.

More from CISA Known Exploited Vulnerabilities