# 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.

- **Severity:** Critical 9.4 (`CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 9 Jul 2026
- **Updated:** 9 Jul 2026
- **Also known as:** GHSA-cfmg-797f-j883

## 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 (Improper Input Validation)

## Which versions are affected by CVE-2025-58146?


## How do I fix CVE-2025-58146?

Apply the vendor's patch.

## Is CVE-2025-58146 being exploited?

There is no known exploitation of CVE-2025-58146 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-58146 and fix it if it is affected.

What it is: 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.
Exploitation: There is no known exploitation of CVE-2025-58146 in the wild and no public exploit code.

Affected product: Xen XAPI. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2025-58146/ (Markdown: https://insights.sbomify.com/CVE-2025-58146/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-58146
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-58146
- OSV: https://osv.dev/vulnerability/CVE-2025-58146

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-58146/
Summaries are generated and may contain mistakes; the official description above is the record.