{"description":"Trending threats, MITRE ATT\u0026CK coverage, and detection metadata — refreshed continuously.","feed_url":"https://feed.craftedsignal.io/tags/cve-2026-40351/","home_page_url":"https://feed.craftedsignal.io/","items":[{"_cs_actors":[],"_cs_cves":[{"cvss":9.8,"id":"CVE-2026-40351"}],"_cs_exploited":false,"_cs_products":[],"_cs_severities":["critical"],"_cs_tags":["NoSQL injection","authentication bypass","CVE-2026-40351","FastGPT"],"_cs_type":"advisory","_cs_vendors":[],"content_html":"\u003cp\u003eFastGPT is an AI Agent building platform. Versions prior to 4.14.9.5 are susceptible to a critical NoSQL injection vulnerability (CVE-2026-40351) affecting the password-based login endpoint. The vulnerability stems from the use of TypeScript type assertion without runtime validation, enabling unauthenticated attackers to inject MongoDB query operators within the password field. This bypasses the intended password check, granting the attacker the ability to authenticate as any user, including the root administrator. Successful exploitation leads to complete control over the FastGPT instance and its associated data. This vulnerability was addressed in FastGPT version 4.14.9.5. All users of FastGPT versions prior to 4.14.9.5 are vulnerable to this attack.\u003c/p\u003e\n\u003ch2 id=\"attack-chain\"\u003eAttack Chain\u003c/h2\u003e\n\u003col\u003e\n\u003cli\u003eAn unauthenticated attacker identifies a vulnerable FastGPT instance running a version prior to 4.14.9.5.\u003c/li\u003e\n\u003cli\u003eThe attacker crafts a malicious HTTP POST request to the password-based login endpoint.\u003c/li\u003e\n\u003cli\u003eWithin the POST request body, the attacker places a MongoDB query operator object (e.g., \u003ccode\u003e{\u0026quot;$ne\u0026quot;: \u0026quot;\u0026quot;}\u003c/code\u003e) in the password field, bypassing the standard password check.\u003c/li\u003e\n\u003cli\u003eThe vulnerable FastGPT application processes the malicious request without proper validation.\u003c/li\u003e\n\u003cli\u003eThe MongoDB query operator is executed, bypassing the authentication mechanism.\u003c/li\u003e\n\u003cli\u003eThe attacker is granted unauthorized access to the FastGPT application, assuming the identity of an arbitrary user, including the root administrator.\u003c/li\u003e\n\u003cli\u003eThe attacker leverages their administrative privileges to access sensitive data, modify configurations, or perform other malicious actions within the FastGPT instance.\u003c/li\u003e\n\u003c/ol\u003e\n\u003ch2 id=\"impact\"\u003eImpact\u003c/h2\u003e\n\u003cp\u003eSuccessful exploitation of CVE-2026-40351 allows an unauthenticated attacker to gain complete control over a FastGPT instance. This can lead to unauthorized access to sensitive AI agent configurations, user data, and other critical information. The impact includes data breaches, service disruption, and potential compromise of downstream systems that rely on the FastGPT platform. Given the critical nature of AI agent building platforms, the compromise of a FastGPT instance can have far-reaching consequences.\u003c/p\u003e\n\u003ch2 id=\"recommendation\"\u003eRecommendation\u003c/h2\u003e\n\u003cul\u003e\n\u003cli\u003eImmediately upgrade all FastGPT instances to version 4.14.9.5 or later to patch CVE-2026-40351.\u003c/li\u003e\n\u003cli\u003eDeploy the Sigma rule \u003ccode\u003eDetect FastGPT NoSQL Injection Attempt\u003c/code\u003e to identify potential exploitation attempts targeting the login endpoint.\u003c/li\u003e\n\u003cli\u003eMonitor web server logs for unusual POST requests to the login endpoint, specifically looking for MongoDB query operators within the password field as detected by rule \u003ccode\u003eDetect FastGPT NoSQL Injection Attempt\u003c/code\u003e.\u003c/li\u003e\n\u003cli\u003eReview and restrict network access to the FastGPT instance to only authorized users and systems to minimize the attack surface.\u003c/li\u003e\n\u003c/ul\u003e\n","date_modified":"2026-04-18T12:00:00Z","date_published":"2026-04-18T12:00:00Z","id":"/briefs/2026-04-fastgpt-nosql-injection/","summary":"FastGPT versions before 4.14.9.5 are vulnerable to NoSQL injection, allowing unauthenticated attackers to bypass authentication and gain administrative access.","title":"FastGPT NoSQL Injection Vulnerability (CVE-2026-40351)","url":"https://feed.craftedsignal.io/briefs/2026-04-fastgpt-nosql-injection/"}],"language":"en","title":"CraftedSignal Threat Feed — CVE-2026-40351","version":"https://jsonfeed.org/version/1.1"}