XML External Entity Vulnerability in thinkgem JeeSite by thinkgem
CVE-2026-3404

2.3LOW

Key Information:

Vendor

Thinkgem

Status
Jeesite
Vendor
CVE Published:
2 March 2026

Badges

👾 Exploit Exists🟡 Public PoC

What is CVE-2026-3404?

A vulnerability exists in the thinkgem JeeSite framework, specifically impacting the CasOutHandler.java file found in the Endpoint component. This flaw allows for XML external entity (XXE) references, potentially leading to sensitive data exposure and Denial of Service (DoS) if exploited. Although the execution of this vulnerability can be complex and is recognized as a remote attack vector, there is an operational exploit available in the public domain. The vendor has been notified about this vulnerability but has not yet provided a response or patch.

Affected Version(s)

JeeSite 5.15.0

JeeSite 5.15.1

Exploit Proof of Concept (PoC)

PoC code is written by security researchers to demonstrate the vulnerability can be exploited. PoC code is also a key component for weaponization which could lead to ransomware.

CVE-2026-3404 - Proof of Concept

References

https://vuldb.com/?id.348299
vdb-entry
https://vuldb.com/?ctiid.348299
signaturepermissions-required
https://vuldb.com/?submit.763732
third-party-advisory

CVSS V4

Score:
2.3
Severity:
LOW
Confidentiality:
Low
Integrity:
Low
Availability:
Low
Attack Vector:
Network
Attack Complexity:
High
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
None

Timeline

  • 🟡

    Public PoC available

  • 👾

    Exploit known to exist

  • Vulnerability published

  • Vulnerability Reserved

Credit

Saul1213 (VulDB User)
VulDB
.