Feathersjs is a framework for creating web APIs and real-time applications with TypeScript or JavaScript. From 5.0.0 to before 5.0.42, Socket.IO clients can send arbitrary JavaScript objects as the id argument to any service method (get, patch, update, remove). The transport layer performs no type checking on this argument. When the service uses the MongoDB adapter, these objects pass through getObjectId() and land directly in the MongoDB query as operators. Sending {$ne: null} as the id matches every document in the collection. This vulnerability is fixed in 5.0.42.

Feathersjs is a framework for creating web APIs and real-time applications with TypeScript or JavaScript. From 5.0.0 to before 5.0.42, an unauthenticated attacker can send a crafted GET request directly to /oauth/:provider/callback with a forged profile in the query string. The OAuth service's authentication payload has a fallback chain that reaches params.query (the raw request query) when Grant's session/state responses are empty. Since the attacker never initiated an OAuth authorize flow, Grant has no session to work with and produces no response, so the fallback fires. The forged profile then drives entity lookup and JWT minting. The attacker gets a valid access token for an existing user without ever contacting the OAuth provider. This vulnerability is fixed in 5.0.42.

Feathersjs is a framework for creating web APIs and real-time applications with TypeScript or JavaScript. In versions 5.0.39 and below, all HTTP request headers are stored in the session cookie, which is signed but not encrypted, exposing internal proxy/gateway headers to clients. The OAuth service stores the complete headers object in the session, then the session is persisted using cookie-session, which base64-encodes the data. While the cookie is signed to prevent tampering, the contents are readable by anyone by simply decoding the base64 value. Under specific deployment configurations (e.g., behind reverse proxies or API gateways), this can lead to exposure of sensitive internal infrastructure details such as API keys, service tokens, and internal IP addresses. This issue has been fixed in version 5.0.40.

Feathersjs is a framework for creating web APIs and real-time applications with TypeScript or JavaScript. In versions 5.0.39 and below, origin validation uses startsWith() for comparison, allowing attackers to bypass the check by registering a domain that shares a common prefix with an allowed origin.The getAllowedOrigin() function checks if the Referer header starts with any allowed origin, and this comparison is insufficient as it only validates the prefix. This is exploitable when the origins array is configured and an attacker registers a domain starting with an allowed origin string (e.g., https://target.com.attacker.com bypasses https://target.com). On its own, tokens are still redirected to a configured origin. However, in specific scenarios an attacker can initiate the OAuth flow from an unauthorized origin and exfiltrate tokens, achieving full account takeover. This issue has bee fixed in version 5.0.40.

Feathersjs is a framework for creating web APIs and real-time applications with TypeScript or JavaScript. Versions 5.0.39 and below the redirect query parameter is appended to the base origin without validation, allowing attackers to steal access tokens via URL authority injection. This leads to full account takeover, as the attacker obtains the victim's access token and can impersonate them. The application constructs the final redirect URL by concatenating the base origin with the user-supplied redirect parameter. This is exploitable when the origins array is configured and origin values do not end with /. An attacker can supply @attacker.com as the redirect value results in https://target.com@attacker.com#access_token=..., where the browser interprets attacker.com as the host, leading to full account takeover. This issue has been fixed in version 5.0.40.

Feathersjs is a framework for creating web APIs and real-time applications with TypeScript or JavaScript. Feathers socket handler did not catch invalid string conversion errors like `const message = ${{ toString: '' }}` which would cause the NodeJS process to crash when sending an unexpected Socket.io message like `socket.emit('find', { toString: '' })`. A fix has been released in versions 5.0.8 and 4.5.18. Users are advised to upgrade. There is no known workaround for this vulnerability.

Due to improper input validation in the Feathers js library, it is possible to perform a SQL injection attack on the back-end database, in case the feathers-sequelize package is used.

Feather-Sequalize cleanQuery method uses insecure recursive logic to filter unsupported keys from the query object. This results in a Remote Code Execution (RCE) with privileges of application.

Due to improper parameter filtering in the Feathers js library, which may ultimately lead to SQL injection