Parse Server is affected by a stored cross-site scripting (XSS) vulnerability in versions >= 9.0.0, < 9.10.0-alpha.2 and <= 8.6.83. When an uploaded file's extension is not recognized by the mime package, Parse Server preserves the client-supplied Content-Type. A malformed Content-Type that is not a valid type/subtype media type (e.g., 'image', 'image/', or 'image//svg+xml') bypasses the fileUpload.fileExtensions blocklist and is stored unchanged. On storage adapters that persist and serve the uploaded Content-Type (such as Amazon S3, Google Cloud Storage, or Azure Blob Storage), a browser cannot parse the malformed value and falls back to MIME-sniffing; a file whose body begins with HTML is rendered as HTML, executing embedded script in the application's origin against other users who open the file URL. The default GridFS storage adapter is not affected. Fixed in 9.10.0-alpha.2 and 8.6.84.
Parse Server is an open source backend that can be deployed to any infrastructure that can run Node.js. Prior to versions 8.6.80 and 9.9.1-alpha.6, a relation query using the $relatedTo operator could read the membership of a Relation field even when that field was hidden from the requesting client by protectedFields, and even when the object owning the relation was not readable by the client under its ACL or class-level permissions. The request requires only the public API credentials that Parse clients normally carry — no user session, master key, or Cloud Code is needed. As a result, an unauthenticated client who knows or obtains the owning object's objectId could enumerate the objects linked through a protected relation, or combine the operator with an objectId constraint to use it as a membership oracle — confirming whether a specific object is linked to a private parent. This affects applications that rely on protectedFields or object ACLs to keep Relation membership confidential, such as private group memberships, block lists, or account-to-resource associations. This issue has been patched in versions 8.6.80 and 9.9.1-alpha.6.
Parse Server is an open source backend that can be deployed to any infrastructure that can run Node.js. Prior to 8.6.76 and 9.9.0, a race condition in the MFA SMS one-time password (OTP) login path allows two concurrent /login requests carrying the same OTP to both succeed and both receive valid session tokens, breaking the single-use property of the OTP. The vulnerability requires the attacker to already possess the victim's password and intercept the active SMS OTP (e.g. via SIM swap, network mirror, or phishing relay) and to race the legitimate login request, so the practical attack surface is narrow. This vulnerability is fixed in 8.6.76 and 9.9.0.
Parse Server is an open source backend that can be deployed to any infrastructure that can run Node.js. Prior to 8.6.73 and 9.7.1, a file can be uploaded with a filename extension that passes the file extension allowlist (e.g., .txt) but with a Content-Type header that differs from the extension (e.g., text/html). The Content-Type is passed to the storage adapter without consistency validation. Storage adapters that store and serve the provided Content-Type (such as S3 or GCS) serve the file with the mismatched Content-Type. The default GridFS adapter is not affected because it derives Content-Type from the filename at serving time. This vulnerability is fixed in 8.6.73 and 9.7.1.
Parse Server is an open source backend that can be deployed to any infrastructure that can run Node.js. Prior to versions 8.6.61 and 9.6.0, an authenticated user calling GET /users/me receives unsanitized auth data, including sensitive credentials such as MFA TOTP secrets and recovery codes. The endpoint internally uses master-level authentication for the session query, and the master context leaks through to the user data, bypassing auth adapter sanitization. An attacker who obtains a user's session token can extract MFA secrets to generate valid TOTP codes indefinitely. This issue has been patched in versions 8.6.61 and 9.6.0
CVE-2026-33624 is a TOCTOU race condition vulnerability in parse-community's parse-server affecting versions prior to 8.6.60 and 9.6.0-alpha.54. An attacker with a user's password and a single MFA recovery code can exploit concurrent login requests to reuse the recovery code multiple times, bypassing its intended single-use restriction. Exploitation requires high privileges (user password), a valid recovery code, and the ability to send rapid concurrent requests. This flaw undermines MFA recovery code security but does not allow unauthorized access without credentials. The vulnerability has a low CVSS score (2.
Parse Server is an open source backend that can be deployed to any infrastructure that can run Node.js. Prior to versions 8.6.57 and 9.6.0, an authenticated user can overwrite server-generated session fields such as expiresAt and createdWith when updating their own session via the REST API. This allows bypassing the server's configured session lifetime policy, making a session effectively permanent. This issue has been patched in versions 8.6.57 and 9.6.0
Parse Server is an open source backend that can be deployed to any infrastructure that can run Node.js. Prior to versions 8.6.56 and 9.6.0, Parse Server's LiveQuery component does not enforce the requestComplexity.queryDepth configuration setting when processing WebSocket subscription requests. An attacker can send a subscription with deeply nested logical operators, causing excessive recursion and CPU consumption that degrades or disrupts service availability. This issue has been patched in versions 8.6.56 and 9.6.0
Parse Server is an open source backend that can be deployed to any infrastructure that can run Node.js. Prior to versions 8.6.53 and 9.6.0, Parse Server's LiveQuery WebSocket interface does not enforce Class-Level Permission (CLP) pointer permissions (readUserFields and pointerFields). Any authenticated user can subscribe to LiveQuery events and receive real-time updates for all objects in classes protected by pointer permissions, regardless of whether the pointer fields on those objects point to the subscribing user. This bypasses the intended read access control, allowing unauthorized access to potentially sensitive data that is correctly restricted via the REST API. This issue has been patched in versions 8.6.53 and 9.6.0
Parse Server is an open source backend that can be deployed to any infrastructure that can run Node.js. Prior to versions 8.6.52 and 9.6.0, an authentication bypass vulnerability allows an attacker to log in as any user who has linked a third-party authentication provider, without knowing the user's credentials. The attacker only needs to know the user's provider ID to gain full access to their account, including a valid session token. This affects Parse Server deployments where the server option allowExpiredAuthDataToken is set to true. The default value is false. This issue has been patched in versions 8.6.52 and 9.6.0
CVE-2026-33323 is a medium-severity vulnerability in parse-community's parse-server prior to versions 8.6.51 and 9.6.0-alpha.40. The issue involves observable response discrepancies in the Pages and legacy PublicAPI routes used for resending email verification links. An unauthenticated attacker can enumerate valid usernames by analyzing different redirect responses depending on whether a username exists and has an unverified email. This vulnerability arises because the emailVerifySuccessOnInvalidEmail configuration, which mitigates enumeration, did not apply to these routes. The flaw allows information disclosure without requiring authentication or user interaction.
Parse Server is an open source backend that can be deployed to any infrastructure that can run Node.js. Prior to 9.6.0 and 8.6.50, when a `Parse.Cloud.afterLiveQueryEvent` trigger is registered for a class, the LiveQuery server leaks protected fields and `authData` to all subscribers of that class. Fields configured as protected via Class-Level Permissions (`protectedFields`) are included in LiveQuery event payloads for all event types (create, update, delete, enter, leave). Any user with sufficient CLP permissions to subscribe to the affected class can receive protected field data of other users, including sensitive personal information and OAuth tokens from third-party authentication providers. The vulnerability was caused by a reference detachment bug. When an `afterEvent` trigger is registered, the LiveQuery server converts the event object to a `Parse.Object` for the trigger, then creates a new JSON copy via `toJSONwithObjects()`. The sensitive data filter was applied to the `Parse.Object` reference, but the unfiltered JSON copy was sent to clients. The fix in versions 9.6.0 and 8.6.50 ensures that the JSON copy is assigned back to the response object before filtering, so the filter operates on the actual data sent to clients. As a workaround, remove all `Parse.Cloud.afterLiveQueryEvent` trigger registrations. Without an `afterEvent` trigger, the reference detachment does not occur and protected fields are correctly filtered.
Parse Server is an open source backend that can be deployed to any infrastructure that can run Node.js. Prior to 9.6.0 and 8.6.48, the password reset mechanism does not enforce single-use guarantees for reset tokens. When a user requests a password reset, the generated token can be consumed by multiple concurrent requests within a short time window. An attacker who has intercepted a password reset token can race the legitimate user's password reset request, causing both requests to succeed. This may result in the legitimate user believing their password was changed successfully while the attacker's password takes effect instead. All Parse Server deployments that use the password reset feature are affected. Starting in versions 9.6.0 and 8.6.48, the password reset token is now atomically validated and consumed as part of the password update operation. The database query that updates the password includes the reset token as a condition, ensuring that only one concurrent request can successfully consume the token. Subsequent requests using the same token will fail because the token has already been cleared. There is no known workaround other than upgrading.
Parse Server is an open source backend that can be deployed to any infrastructure that can run Node.js. Prior to 9.6.0 and 8.6.44, an attacker can bypass the default request keyword denylist protection and the class-level permission for adding fields by sending a crafted request that exploits prototype pollution in the deep copy mechanism. This allows injecting fields into class schemas that have field addition locked down, and can cause permanent schema type conflicts that cannot be resolved even with the master key. In 9.6.0 and 8.6.44, the vulnerable third-party deep copy library has been replaced with a built-in deep clone mechanism that handles prototype properties safely, allowing the existing denylist check to correctly detect and reject the prohibited keyword. No known workarounds are available.
Parse Server is an open source backend that can be deployed to any infrastructure that can run Node.js. Prior to 9.6.0 and 8.6.43, a remote attacker can crash the Parse Server by subscribing to a LiveQuery with an invalid regular expression pattern. The server process terminates when the invalid pattern reaches the regex engine during subscription matching, causing denial of service for all connected clients. The fix in 9.6.0 and 8.6.43 validates regular expression patterns at subscription time, rejecting invalid patterns before they are stored. Additionally, a defense-in-depth try-catch prevents any subscription matching error from crashing the server process. As a workaround, disable LiveQuery if it is not needed.
Parse Server is an open source backend that can be deployed to any infrastructure that can run Node.js. Prior to 9.6.0 and 8.6.41, an attacker who is allowed to upload files can bypass the file extension filter by appending a MIME parameter (e.g. `;charset=utf-8`) to the `Content-Type` header. This causes the extension validation to fail matching against the blocklist, allowing active content to be stored and served under the application's domain. In addition, certain XML-based file extensions that can render scripts in web browsers are not included in the default blocklist. This can lead to stored XSS attacks, compromising session tokens, user credentials, or other sensitive data accessible via the browser's local storage. The fix in versions 9.6.0 and 8.6.41 strips MIME parameters from the `Content-Type` header before validating the file extension against the blocklist. The default blocklist has also been extended to include additional XML-based extensions (`xsd`, `rng`, `rdf`, `rdf+xml`, `owl`, `mathml`, `mathml+xml`) that can render active content in web browsers. Note that the `fileUpload.fileExtensions` option is intended to be configured as an allowlist of file extensions that are valid for a specific application, not as a denylist. The default denylist is provided only as a basic default that covers most common problematic extensions. It is not intended to be an exhaustive list of all potentially dangerous extensions. Developers should not rely on the default value, as new extensions that can render active content in browsers might emerge in the future. As a workaround, configure the `fileUpload.fileExtensions` option to use an allowlist of only the file extensions that your application needs, rather than relying on the default blocklist.
CVE-2026-32269 is a medium severity vulnerability in parse-community's parse-server affecting versions prior to 9.6.0-alpha.13 and 8.6.39. The OAuth2 authentication adapter incorrectly validates app IDs when appidField and appIds are configured, sending malformed values to the token introspection endpoint instead of the user's actual access token. This flaw can cause OAuth2 logins to fail or, depending on the introspection endpoint's response, allow unauthorized authentication from disallowed app contexts. Exploitation does not require privileges or user interaction but has a high attack complexity. The vulnerability impacts deployments using the OAuth2 adapter with specific configurations and is fixed in the indicated patched versions.
Parse Server is an open source backend that can be deployed to any infrastructure that can run Node.js. Prior to 9.6.0 and 8.6.38, an unauthenticated attacker can take over any user account that was created with an authentication provider that does not validate the format of the user identifier (e.g. anonymous authentication). By sending a crafted login request, the attacker can cause the server to perform a pattern-matching query instead of an exact-match lookup, allowing the attacker to match an existing user and obtain a valid session token for that user's account. Both MongoDB and PostgreSQL database backends are affected. Any Parse Server deployment that allows anonymous authentication (enabled by default) is vulnerable. This vulnerability is fixed in 9.6.0 and 8.6.38.
Parse Server is an open source backend that can be deployed to any infrastructure that can run Node.js. Prior to 9.6.0 and 8.6.36, an attacker with access to the master key can inject malicious SQL via crafted field names used in query constraints when Parse Server is configured with PostgreSQL as the database. The field name in a $regex query operator is passed to PostgreSQL using unparameterized string interpolation, allowing the attacker to manipulate the SQL query. While the master key controls what can be done through the Parse Server abstraction layer, this SQL injection bypasses Parse Server entirely and operates at the database level. This vulnerability only affects Parse Server deployments using PostgreSQL. This vulnerability is fixed in 9.6.0 and 8.6.36.
Parse Server is an open source backend that can be deployed to any infrastructure that can run Node.js. Prior to 9.6.0 and 8.6.35, an attacker can exploit LiveQuery subscriptions to infer the values of protected fields without directly receiving them. By subscribing with a WHERE clause that references a protected field (including via dot-notation or $regex), the attacker can observe whether LiveQuery events are delivered for matching objects. This creates a boolean oracle that leaks protected field values. The attack affects any class that has both protectedFields configured in Class-Level Permissions and LiveQuery enabled. This vulnerability is fixed in 9.6.0 and 8.6.35.