Insecure Direct Object Reference in TDuck Survey Form from TDuckCloud
CVE-2026-109167

5.3MEDIUM

Key Information:

Vendor

Tduckcloud

Status
Tduck-survey-form
Vendor
CVE Published:
12 October 2026

Badges

👾 Exploit Exists🟡 Public PoC

What is CVE-2026-109167?

The TDuck survey form version 6.0 has a vulnerability that allows authenticated users to exploit an insecure direct object reference in the saveFormTheme handler. This flaw enables attackers to overwrite the themes of other users' forms by submitting their own formKey along with a sequential theme ID associated with a victim's form. This action can change the appearance of the forms by replacing the colours and image URLs, effectively removing the victim's custom theme and impacting the integrity of user-generated content.

Affected Version(s)

tduck-survey-form 0 <= 6.0

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-2026-109167 - Proof of Concept

References

https://github.com/AnkesKasty/cve-request-poc/blob/a7b6d1...
exploit
https://github.com/TDuckCloud/tduck-survey-form/blob/43ff...
technical-description
https://www.vulncheck.com/advisories/tduck-survey-form-th...
third-party-advisory

CVSS V4

Score:
5.3
Severity:
MEDIUM
Confidentiality:
None
Integrity:
Low
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
None

Timeline

  • 🟡

    Public PoC available

  • 👾

    Exploit known to exist

  • Vulnerability published

  • Vulnerability Reserved

Credit

Yaqi Chao
.