Attack Chain

1. Attacker discovers an internet-accessible 9Router instance running an affected version (0.4.41 or earlier).
2. Attacker sends an unauthenticated HTTP GET request to the /request-logs API endpoint (e.g., GET /request-logs).
3. The vulnerable 9Router instance responds with paginated request logs, which include requestId values for past conversations, due to the lack of proper authentication controls.
4. Attacker parses the received logs to extract valid requestId values associated with user interactions.
5. Attacker crafts and sends subsequent unauthenticated HTTP GET requests to the /request-details API endpoint, appending an extracted requestId as a query parameter (e.g., GET /request-details?requestId=ABC-123).
6. The 9Router instance, still lacking authentication middleware for this endpoint, responds with the complete AI conversation history corresponding to the requestId. This data includes system prompts, user messages, assistant responses, tool calls, and associated user email addresses.
7. Attacker continuously queries various requestId values to collect a large volume of sensitive user data, leading to unauthorized data exfiltration.

Impact

Successful exploitation of CVE-2026-62328 leads to the unauthorized disclosure of highly sensitive user information. Attackers can retrieve full AI conversation histories, including private discussions, proprietary system prompts, and detailed interactions between users and the AI. Crucially, user email addresses are also exposed, increasing the risk of targeted phishing, identity theft, or further malicious activities. The number of potential victims corresponds to the user base of affected 9Router instances, with the scope of data exposure depending on the volume of logged requests. The core damage involves a severe breach of data confidentiality and user privacy.

Recommendation

• Patch CVE-2026-62328 immediately by upgrading 9Router to version 0.4.42 or later.
• Deploy the provided Sigma rules to your SIEM to detect attempts to access the vulnerable API endpoints.
• Enable comprehensive web server logging for HTTP requests, particularly for cs-uri-stem and cs-method, to activate the detection rules.
• Review web server access logs for any unauthenticated or suspicious GET requests to /request-logs or /request-details from external IP addresses.