What’s Vulnerable › Vulnerabilities

CVE-2026-111707: 99AI through 4.3.0 IDOR via /api/chatLog/querySingleChat Chat Message Disclosure

• Severity: medium (CVSS 5.3 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.3% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-10-16 · updated 2026-10-16
• Weakness: CWE-639

Description

99AI through 4.3.0 contains an insecure direct object reference vulnerability that allows unauthenticated attackers to read other users' chat messages because querySingleChat lacks an owner check. Attackers can send a fingerprint header to obtain a visitor JWT and iterate sequential chatId values to retrieve other users' message content and task data.

Affected products

• vastxie 99AI: through 4.3.0

References

• https://github.com/vastxie/99AI
• https://github.com/vastxie/99AI/blob/v4.3.0/service/src/common/auth/jwtAuth.guard.ts
• https://github.com/vastxie/99AI/blob/v4.3.0/service/src/modules/chatLog/chatLog.service.ts#L463-L475
• https://hackmd.io/@hieuPenguinnn/99ai-chatlog-unauth-export-and-idor
• https://www.vulncheck.com/advisories/99ai-through-4.3.0-idor-via-api-chatlog-querysinglechat-chat-message-disclosure
• https://hackmd.io/@hieuPenguinnn/99ai-chatlog-unauth-export-and-idor

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