Flask-AppBuilder is a development framework, built on top of Flask. User enumeration in database authentication in Flask-AppBuilder <= 3.2.3. Allows for a non authenticated user to enumerate existing accounts by timing the response time from the server when you are logging in. Upgrade to version 3.3.0 or higher to resolve.

Parse Server is an open source backend that can be deployed to any infrastructure that can run Node.js. Prior to versions 8.6.54 and 9.6.0-alpha.43, an attacker can subscribe to LiveQuery with a watch parameter targeting a protected field. Although the protected field value is properly stripped from event payloads, the presence or absence of update events reveals whether the protected field changed, creating a binary oracle. For boolean protected fields, the timing of change events is equivalent to knowing the field value. This issue has been patched in versions 8.6.54 and 9.6.0-alpha.43.

WWBN AVideo is an open source video platform. In versions up to and including 26.0, the password recovery endpoint at `objects/userRecoverPass.php` performs user existence and account status checks before validating the captcha. This allows an unauthenticated attacker to enumerate valid usernames and determine whether accounts are active, inactive, or banned — at scale and without solving any captcha — by observing three distinct JSON error responses. Commit e42f54123b460fd1b2ee01f2ce3d4a386e88d157 contains a patch.

Discourse is an open-source discussion platform. Prior to versions 2026.3.0-latest.1, 2026.2.1, and 2026.1.2, unauthenticated users can determine whether a specific user is a member of a private group by observing changes in directory results when using the `exclude_groups` parameter. Versions 2026.3.0-latest.1, 2026.2.1, and 2026.1.2 contain a patch. As a workaround, disable public access to the user directory via Admin → Settings → hide user profiles from public.

In Directus 8.x through 8.8.1, an attacker can discover whether a user is present in the database through the password reset feature. NOTE: This vulnerability only affects products that are no longer supported by the maintainer

Parse Server is an open source backend that can be deployed to any infrastructure that can run Node.js. Prior to 8.6.34 and 9.6.0-alpha.8, the email verification endpoint (/verificationEmailRequest) returns distinct error responses depending on whether an email address belongs to an existing user, is already verified, or does not exist. An attacker can send requests with different email addresses and observe the error codes to determine which email addresses are registered in the application. This is a user enumeration vulnerability that affects any Parse Server deployment with email verification enabled (verifyUserEmails: true). This vulnerability is fixed in 8.6.34 and 9.6.0-alpha.8.

Shopware is an open commerce platform. Prior to 6.7.8.1 and 6.6.10.15, the Store API login endpoint (POST /store-api/account/login) returns different error codes depending on whether the submitted email address belongs to a registered customer (CHECKOUT__CUSTOMER_AUTH_BAD_CREDENTIALS) or is unknown (CHECKOUT__CUSTOMER_NOT_FOUND). The "not found" response also echoes the probed email address. This allows an unauthenticated attacker to enumerate valid customer accounts. The storefront login controller correctly unifies both error paths, but the Store API does not — indicating an inconsistent defense. This vulnerability is fixed in 6.7.8.1 and 6.6.10.15.

Chamilo LMS is a learning management system. Prior to version 1.11.36, Chamilo is vulnerable to user enumeration with valid/invalid username. This issue has been patched in version 1.11.36.

Dify is an open-source LLM app development platform. Prior to 1.9.0, responses from the Dify API to existing and non-existent accounts differ, allowing an attacker to enumerate email addresses registered with Dify. Version 1.9.0 fixes the issue.

NocoDB is software for building databases as spreadsheets. Prior to version 0.301.3, the password forgot endpoint returned different responses for registered and unregistered emails, allowing user enumeration. This issue has been patched in version 0.301.3.

Static Web Server (SWS) is a production-ready web server suitable for static web files or assets. In versions 2.1.0 through 2.40.1, a timing-based username enumeration vulnerability in Basic Authentication allows attackers to identify valid users by exploiting early responses for invalid usernames, enabling targeted brute-force or credential-stuffing attacks. SWS checks whether a username exists before verifying the password, causing valid usernames to follow a slower code path (e.g., bcrypt hashing) while invalid usernames receive an immediate 401 response. This timing discrepancy allows attackers to enumerate valid accounts by measuring response-time differences. This issue has been fixed in version 2.41.0.

Jenkins GitHub Plugin 1.34.4 and earlier uses a non-constant time comparison function when checking whether the provided and computed webhook signatures are equal, allowing attackers to use statistical methods to obtain a valid webhook signature.

User enumeration vulnerability in /pwreset.php in osTicket v1.18.2 allows remote attackers to enumerate valid usernames registered in the platform.

Rucio is a software framework that provides functionality to organize, manage, and access large volumes of scientific data using customizable policies. Prior to versions 35.8.3, 38.5.4, and 39.3.1, the WebUI login endpoint returns distinct error messages depending on whether a supplied username exists, allowing unauthenticated attackers to enumerate valid usernames. Versions 35.8.3, 38.5.4, and 39.3.1 fix the issue.

The Open eClass platform (formerly known as GUnet eClass) is a complete course management system. Prior to version 4.2, a username enumeration vulnerability allows unauthenticated attackers to identify valid user accounts by analyzing differences in the login response behavior. This issue has been patched in version 4.2.

File Browser provides a file managing interface within a specified directory and can be used to upload, delete, preview, rename, and edit files. Prior to version 2.55.0, the JSONAuth. Auth function contains a logic flaw that allows unauthenticated attackers to enumerate valid usernames by measuring the response time of the /api/login endpoint. The vulnerability exists due to a "short-circuit" evaluation in the authentication logic. When a username is not found in the database, the function returns immediately. However, if the username does exist, the code proceeds to verify the password using bcrypt (users.CheckPwd), which is a computationally expensive operation designed to be slow. This difference in execution path creates a measurable timing discrepancy. Version 2.55.0 contains a patch for the issue.

A vulnerability in an identity management API endpoint of Cisco ISE could allow an unauthenticated, remote attacker to enumerate valid user accounts on an affected device. This vulnerability exists because error messages are observed when the affected API endpoint is called. An attacker could exploit this vulnerability by sending a series of crafted requests to the affected endpoint and analyzing the differentiated responses. A successful exploit could allow the attacker to compile a list of valid usernames on an affected system.

AnythingLLM is an application that turns pieces of content into context that any LLM can use as references during chatting. Prior to commit e287fab56089cf8fcea9ba579a3ecdeca0daa313, the password recovery endpoint returns different error messages depending on whether a username exists, so enabling username enumeration. Commit e287fab56089cf8fcea9ba579a3ecdeca0daa313 fixes this issue.

Dependency-Track is a Component Analysis platform that allows organizations to identify and reduce risk in the software supply chain. Performing a login request against the /api/v1/user/login endpoint with a username that exist in the system takes significantly longer than performing the same action with a username that is not known by the system. The observable difference in request duration can be leveraged by actors to enumerate valid names of managed users. LDAP and OpenID Connect users are not affected. The issue has been fixed in Dependency-Track 4.12.2.

In Gitea before 1.25.2, /api/v1/user has different responses for failed authentication depending on whether a username exists.

The login mechanism of Sage DPW 2021_06_004 displays distinct responses for valid and invalid usernames, allowing enumeration of existing accounts in versions before 2021_06_000. On-premise administrators can toggle this behavior in newer versions.

OpenAEV is an open source platform allowing organizations to plan, schedule and conduct cyber adversary simulation campaign and tests. Starting in version 1.11.0 and prior to version 2.0.13, the /api/reset endpoint behaves differently depending on whether the supplied username exists in the system. When a non-existent email is provided in the login parameter, the endpoint returns an HTTP 400 response (Bad Request). When a valid email is supplied, the endpoint responds with HTTP 200. This difference in server responses creates an observable discrepancy that allows an attacker to reliably determine which emails are registered in the application. By automating requests with a list of possible email addresses, an attacker can quickly build a list of valid accounts without any authentication. The endpoint should return a consistent response regardless of whether the username exists in order to prevent account enumeration. Version 2.0.13 fixes this issue.

Kalmia CMS version 0.2.0 contains a user enumeration vulnerability in its authentication mechanism. The application returns different error messages for invalid users (user_not_found) versus valid users with incorrect passwords (invalid_password). This observable response discrepancy allows unauthenticated attackers to enumerate valid usernames on the system.

A Observable Response Discrepancy vulnerability in spacewalk-java of SUSE Manager Server 4.1, SUSE Manager Server 4.2 allows remote attackers to discover valid usernames. This issue affects: SUSE Manager Server 4.1 spacewalk-java versions prior to 4.1.46-1. SUSE Manager Server 4.2 spacewalk-java versions prior to 4.2.37-1.

The Frontier Airlines website has a publicly available endpoint that validates if an email addresses is associated with an account. An unauthenticated, remote attacker could determine valid email addresses, possibly aiding in further attacks.

Windu CMS is vulnerable to User Enumeration. This issue occurs during logon, where a difference in messages could allow an attacker to determine if the login is valid or not, enabling a brute force attack with valid logins. Only version 4.1 was tested and confirmed as vulnerable. This issue was fixed in version 4.1 build 2250.

ownCloud Guests before 0.12.5 allows unauthenticated user enumeration via the /apps/guests/register/{email}/{token} endpoint. Because of insufficient validation of the supplied token in showPasswordForm, the server responds differently when an e-mail address corresponds to a valid pending guest user rather than a non-existent user.

For failed login attempts, the application returns different error messages depending on whether the login failed due to an incorrect password or a non-existing username. This allows an attacker to guess usernames until they find an existing one.

The open-source identity infrastructure software Zitadel allows administrators to disable the user self-registration. Versions 4.0.0 to 4.0.2, 3.0.0 to 3.3.6, and all versions prior to 2.71.15 are vulnerable to a username enumeration issue in the login interface. The login UI includes a security feature, Ignoring unknown usernames, that is intended to prevent username enumeration by returning a generic response for both valid and invalid usernames. This vulnerability allows an unauthenticated attacker to bypass this protection by submitting arbitrary userIDs to the select account page and distinguishing between valid and invalid accounts based on the system's response. For effective exploitation, an attacker needs to iterate through possible userIDs, but the impact can be limited by implementing rate limiting or similar measures. The issue has been patched in versions 4.0.3, 3.4.0, and 2.71.15.

Trivision NC-227WF firmware 5.80 (build 20141010) login mechanism reveals whether a username exists or not by returning different error messages ("Unknown user" vs. "Wrong password"), allowing an attacker to enumerate valid usernames.

By checking the result of calls to `window.open` with specifically set protocol handlers, an attacker could determine if the application which implements that protocol handler is installed. This vulnerability affects Firefox < 131, Firefox ESR < 128.3, Thunderbird < 128.3, and Thunderbird < 131.

An issue in Austrian Academy of Sciences (AW) Austrian Archaeological Institute OpenAtlas v.8.12.0 allows a remote attacker to obtain sensitive information via the login error messages

Improper handling of authentication requests lead to a user enumeration vector in the passkey authentication method.

A vulnerability in the RADIUS authentication module of Cisco Policy Suite could allow an unauthenticated, remote attacker to determine whether a subscriber username is valid. The vulnerability occurs because the Cisco Policy Suite RADIUS server component returns different authentication failure messages based on the validity of usernames. An attacker could use these messages to determine whether a valid subscriber username has been identified. The attacker could use this information in subsequent attacks against the system. Cisco Bug IDs: CSCvg47830.

Tuleap is an Open Source Suite created to facilitate management of software development and collaboration. In Tuleap Community Edition prior to version 16.9.99.1750843170 and Tuleap Enterprise Edition prior to 16.8-4 and 16.9-2, the forgot password form allows for user enumeration. This is fixed in Tuleap Community Edition version 16.9.99.1750843170 and Tuleap Enterprise Edition 16.8-4 and 16.9-2.

Kanboard is project management software that focuses on the Kanban methodology. Prior to version 1.2.46, Kanboard is vulnerable to username enumeration and IP spoofing-based brute-force protection bypass. By analyzing login behavior and abusing trusted HTTP headers, an attacker can determine valid usernames and circumvent rate-limiting or blocking mechanisms. Any organization running a publicly accessible Kanboard instance is affected, especially if relying on IP-based protections like Fail2Ban or CAPTCHA for login rate-limiting. Attackers with access to the login page can exploit this flaw to enumerate valid usernames and bypass IP-based blocking mechanisms, putting all user accounts at higher risk of brute-force or credential stuffing attacks. Version 1.2.46 contains a patch for the issue.

IBM Security Verify Access Appliance and Docker 10.0 through 10.0.8 could allow a remote attacker to enumerate usernames due to an observable response discrepancy of disabled accounts.

Dropbear 2011.54 through 2018.76 has an inconsistent failure delay that may lead to revealing valid usernames, a different issue than CVE-2018-15599.

For failed login attempts, the application returns different error messages depending on whether the login failed due to an incorrect password or a non-existing username. This allows an attacker to guess usernames until they find an existing one.

A vulnerability in NetCat CMS allows an attacker to send a specially crafted http request that can be used to check whether a user exists in the system, which could be a basis for further attacks. This issue affects NetCat CMS v. 6.4.0.24126.2 and possibly others. Apply patch from vendor https://netcat.ru/ https://netcat.ru/] . Versions 6.4.0.24248 and on have the patch.

Umbraco is a free and open source .NET content management system. Prior to versions 10.8.10 and 13.8.1, based on an analysis of the timing of post login API responses, it's possible to determine whether an account exists. The issue is patched in versions 10.8.10 and 13.8.1. No known workarounds are available.

Enumeration of ERC from object entry in Liferay Portal 7.4.0 through 7.4.3.128, and Liferay DXP 2024.Q3.0 through 2024.Q3.1, 2024.Q2.0 through 2024.Q2.13, 2024.Q1.1 through 2024.Q1.12, 2023.Q4.0 and 7.4 GA through update 92 allow attackers to determine existent ERC in the application by exploit the time response.

User enumeration vulnerability in Liferay Portal 7.4.0 through 7.4.3.132, and Liferay DXP 2024.Q4.0 through 2024.Q4.7, 2024.Q3.0 through 2024.Q3.13, 2024.Q2.0 through 2024.Q2.13, 2024.Q1.1 through 2024.Q1.14, 2023.Q4.0 through 2023.Q4.10, 2023.Q3.1 through 2023.Q3.10 and 7.4 GA through update 92 allows remote attackers to determine if an account exist in the application via the create account page.

Snipe-IT through 6.0.14 allows attackers to check whether a user account exists because of response variations in a /password/reset request.

User enumeration in Nagvis' Checkmk MultisiteAuth before version 1.9.48 allows an unauthenticated attacker to enumerate Checkmk usernames.

A vulnerability was found in nasirkhan Laravel Starter up to 11.8.0. It has been rated as problematic. Affected by this issue is some unknown functionality of the file /forgot-password of the component Password Reset Handler. The manipulation of the argument Email leads to observable response discrepancy. The attack may be launched remotely. The complexity of an attack is rather high. The exploitation is known to be difficult. The exploit has been disclosed to the public and may be used. The identifier of this vulnerability is VDB-268784. NOTE: The vendor was contacted early about this disclosure but did not respond in any way.

A website was able to detect when a user took a screenshot of a page using the built-in Screenshot functionality in Firefox. This vulnerability affects Firefox < 127.

Jenkins GitLab Plugin 1.5.35 and earlier uses a non-constant time comparison function when checking whether the provided and expected webhook token are equal, potentially allowing attackers to use statistical methods to obtain a valid webhook token.

A vulnerability has been identified in Desigo DXR2 (All versions < V01.21.142.5-22), Desigo PXC3 (All versions < V01.21.142.4-18), Desigo PXC4 (All versions < V02.20.142.10-10884), Desigo PXC5 (All versions < V02.20.142.10-10884). The login functionality of the application fails to normalize the response times of login attempts performed with wrong usernames with the ones executed with correct usernames. A remote unauthenticated attacker could exploit this side-channel information to perform a username enumeration attack and identify valid usernames.

D-Link Nuclias Connect firmware versions <= 1.3.1.4 contain an observable response discrepancy vulnerability. The application's 'Forgot Password' endpoint returns distinct JSON responses depending on whether the supplied email address is associated with an existing account. Because the responses differ in the `data.exist` boolean value, an unauthenticated remote attacker can enumerate valid email addresses/accounts on the server. NOTE: D-Link states that a fix is under development.