CVE-2025-58146 XAPI UTF-8 string handling
Improper UTF-8 handling and missing sanitization in Xen XAPI can crash the event thread or corrupt the database, causing denial of service.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2025-58146?
CVE-2025-58146 is a critical denial of service vulnerability in Xen XAPI, published on 9 Jul 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
There are multiple issues.
1. Updates to the XAPI database sanitise input strings, but try generating the notification using the unsanitised input. This causes the database's event thread to terminate and cease further processing.
2. XAPI's UTF-8 encoder implements v3.0 of the Unicode spec, but XAPI uses libraries which conform to the stricter v3.1 of the Unicode spec. This causes some strings to be accepted as valid UTF-8 by XAPI, but rejected by other libraries in use. Notably, such strings can be entered into the database, after which the database can no longer be loaded.
3. There is no input sanitisation for Map/Set updates on objects in the XAPI database.
Weakness: CWE-20
Which versions are affected by CVE-2025-58146?
How do I fix CVE-2025-58146?
Apply the vendor's patch.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2025-58146 being exploited?
There is no known exploitation of CVE-2025-58146 in the wild and no public exploit code.
Sources
Also known as GHSA-cfmg-797f-j883.