Quick answers
- Is CVE-2023-54398 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2023-54398 being exploited in the wild.
- How severe is CVE-2023-54398?
- Critical severity, with a CVSS score of 9.8, published 15 September 2026.
- Which products and versions are affected?
- Yonyou U8 Cloud <unknown>.
- Is there a fix for CVE-2023-54398?
- No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
- How is CVE-2023-54398 attacked?
- It is attacked over the network.
- Am I affected by CVE-2023-54398?
- Check whether you run Yonyou U8 Cloud at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
Technical details
The vulnerability is a Java deserialization flaw in the FileManageServlet component (doAction method) that accepts serialized Java objects via POST requests without authentication or validation. The vulnerable code passes raw HTTP request body data directly to ObjectInputStream.readObject(), allowing attackers to deserialize malicious payloads containing arbitrary OS commands. The attack requires only network access to the web service; no authentication credentials are needed. Successful exploitation results in remote code execution with the privileges of the application server process. Patch availability status is not mentioned in the advisory.
Affected products
- Yonyou U8 Cloud <unknown>
Timeline
- 2026-09-15: disclosed
- 2025-02-13: exploited: Exploitation observed by Shadowserver Foundation