Is itCheck something

No. CVE-2023-49105

A ownCloud bug is being used in attacks

Being used now

Yes. Attackers are using this right now.

What to do

Apply the vendor's update. If there is none, stop using it or cut it off from the internet.

Confirmed in attacks
Aug 27, 2026
Product
ownCloud
Attack likelihood, next 30 days
43%

Attack likelihood is EPSS, a daily estimate from FIRST.org of how likely this bug is to be used in attacks in the next 30 days.

The official description

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.

For your tech helper

A read-only checklist for whoever helps you with your computer, or an AI assistant. Paste it into Claude, ChatGPT or a coding agent; it only looks and changes nothing.

Read-only check, change nothing, send nothing anywhere.
Is ownCloud ownCloud (CVE-2023-49105) installed or running on this machine or in this project?
1. Find every copy and its version (apps, packages, containers, lockfiles).
2. Compare each version against the vendor's fixed version for CVE-2023-49105. Quote the vendor page you used.
3. Report a table: where, version, fixed version, status (exposed / fixed / not installed / unsure).
4. List the exact update steps, but do not run them.

Sources