Insecure Direct Object Reference in 99AI by VastXie
CVE-2026-111707

6.9MEDIUM

Key Information:

Vendor

Vastxie

Status
99ai
Vendor
CVE Published:
16 October 2026

What is CVE-2026-111707?

99AI versions up to 4.3.0 are affected by an insecure direct object reference vulnerability. This flaw enables unauthenticated attackers to access other users' chat messages due to a missing owner check in the querySingleChat function. By exploiting this vulnerability, attackers can craft specific requests, utilizing a fingerprint header to obtain a visitor JWT. They can iteratively modify chatId values to extract confidential message content and associated task data from the system.

Affected Version(s)

99AI 0 <= 4.3.0

References

https://hackmd.io/@hieuPenguinnn/99ai-chatlog-unauth-expo...
third-party-advisory
https://github.com/vastxie/99AI/blob/v4.3.0/service/src/m...
technical-description
https://github.com/vastxie/99AI/blob/v4.3.0/service/src/c...
technical-description

CVSS V4

Score:
6.9
Severity:
MEDIUM
Confidentiality:
Low
Integrity:
None
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
None

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

hieuPenguinnn
.