CVE-2025-4260Public exploitNetwork attack vector

Authenticated DNS callbacks via unsafe Java deserialization

Published May 5, 2025 · Updated May 5, 2025

Unsafe deserialization in Youkefu 4.0, 4.1, and 4.2.0 allows remote authenticated users to trigger attacker-controlled DNS lookups. TemplateController.impsave passes the unvalidated dataFile request value to UKTools.toObject, whose ObjectInputStream.readObject call reconstructs attacker-supplied Java objects. The administrative endpoint requires low-privilege access, and the public URLDNS proof of concept demonstrates outbound DNS activity rather than code execution.

CVSS severity8.3
High
EPSS probability0.68%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Unsafe deserialization in Youkefu 4.0, 4.1, and 4.2.0 allows remote authenticated users to trigger attacker-controlled DNS lookups. TemplateController.impsave passes the unvalidated dataFile request value to UKTools.toObject, whose ObjectInputStream.readObject call reconstructs attacker-supplied Java objects. The administrative endpoint requires low-privilege access, and the public URLDNS proof of concept demonstrates outbound DNS activity rather than code execution.

The record

CVE
CVE-2025-4260
Published
May 5, 2025
Updated
May 5, 2025
Vendor
Zhangyanbo2007
Product
Youkefu
Classifications
CWE-20, CWE-502, T1190
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. May 5, 2025CVE publishedPublication date reported by the CVE source.
  2. May 5, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=4.0
  2. Affected versionversion=4.1
  3. Affected versionversion=4.2.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Zhangyanbo2007 · Youkefuversion=4.0; version=4.1; version=4.2.0

Published CVSS scores

4.3VulDBCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
4.0VulDBAV:N/AC:L/Au:S/C:P/I:N/A:N
5.3VulDBCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N
8.3NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-20Improper Input Validation
CWE-502Deserialization of Untrusted Data
T1190Exploit Public-Facing Application

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo