CVE-2026-111707 vastxie CVE debrief

Who should care

Defenders responsible for 99AI deployments, particularly those with sensitive information exchanged through chat logs, should assess potential exposure and implement additional security measures to prevent unauthorized access.

Why it matters

CVE-2026-111707 is a medium-severity vulnerability in 99AI that allows unauthenticated attackers to read other users' chat messages, potentially leading to sensitive information disclosure and data breaches.

• Potential unauthorized access to sensitive information in chat logs
• Increased risk of data breaches or information disclosure
• Need for additional authentication and authorization checks for chat log access
• Potential for lateral movement or further exploitation

Technical summary

The 99AI application through version 4.3.0 contains an insecure direct object reference (IDOR) vulnerability in the /api/chatLog/querySingleChat endpoint. This vulnerability allows unauthenticated attackers to read other users' chat messages by iterating sequential chatId values. The vulnerability has a CVSS score of 6.9 and is considered medium-severity. The IDOR vulnerability enables attackers to obtain a visitor JWT and iterate sequential chatId values to retrieve other users' message content and task data. Defenders should prioritize verifying exposure of 99AI chat logs and assessing potential unauthorized access to sensitive information.

Defensive priority

Defenders should prioritize verifying exposure of 99AI chat logs and assessing potential unauthorized access to sensitive information.

Recommended defensive actions

• Verify 99AI deployment exposure to unauthorized chat log access
• Assess potential impact of sensitive information disclosure
• Implement additional authentication and authorization checks for chat log access
• Monitor for suspicious activity related to chat log queries
• Review compensating controls for exposed systems while remediation is scheduled and verified
• Check relevant monitoring, detection, and logs for exposed assets that need extra review
• Track exceptions, retest remediated assets, and close the item only after evidence is documented

Evidence notes

The CVE record and source item provide details on the IDOR vulnerability in 99AI, allowing unauthenticated attackers to read other users' chat messages by iterating sequential chatId values in the /api/chatLog/querySingleChat endpoint. Evidence is limited to the CVE record and source item, which describe the vulnerability and its potential impact. Defenders should verify exposure of 99AI chat logs and assess potential unauthorized access to sensitive information. The vulnerability has a CVSS score of 6.9 and is considered medium-sever

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.