An observable response discrepancy vulnerability [CWE-204] in FortiClientEMS 7.4.0, 7.2.0 through 7.2.4, 7.0 all versions, and FortiSOAR 7.5.0, 7.4.0 through 7.4.4, 7.3.0 through 7.3.2, 7.2 all versions, 7.0 all versions, 6.4 all versions may allow an unauthenticated attacker to enumerate valid users via observing login request responses.

IBM Control Center 6.2.1 and 6.3.1 could allow a remote attacker to enumerate usernames due to an observable discrepancy between login attempts.

IBM i 7.2, 7.3, 7.4, and 7.5 Service Tools Server (SST) is vulnerable to SST user enumeration by a remote attacker. This vulnerability can be used by a malicious actor to gather information about SST users that can be targeted in further attacks. IBM X-Force ID: 287538.

In Logpoint before 7.4.0, an attacker can enumerate a valid list of usernames by using publicly exposed URLs of shared widgets.

Piccolo is an ORM and query builder which supports asyncio. In versions 0.120.0 and prior, the implementation of `BaseUser.login` leaks enough information to a malicious user such that they would be able to successfully generate a list of valid users on the platform. As Piccolo on its own does not also enforce strong passwords, these lists of valid accounts are likely to be used in a password spray attack with the outcome being attempted takeover of user accounts on the platform. The impact of this vulnerability is minor as it requires chaining with other attack vectors in order to gain more then simply a list of valid users on the underlying platform. The likelihood of this vulnerability is possible as it requires minimal skills to pull off, especially given the underlying login functionality for Piccolo based sites is open source. This issue has been patched in version 0.121.0.

User enumeration can occur in the Authentication REST API in Delinea PAM Secret Server 11.4. This allows a remote attacker to determine whether a user is valid because of a difference in responses from the /oauth2/token endpoint.

Proxmox VE prior to 3.2: 'AccessControl.pm' User Enumeration Vulnerability

An user enumeration vulnerability was found in SEO Panel 4.10.0. This issue occurs during user authentication, where a difference in error messages could allow an attacker to determine if a username is valid or not, enabling a brute-force attack with valid usernames.

Jenkins Generic Webhook Trigger Plugin 1.84.1 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.

Fixed in v1.5.1, Argo version v1.5.0 was vulnerable to a user-enumeration vulnerability which allowed attackers to determine the usernames of valid (non-SSO) accounts because /api/v1/session returned 401 for an existing username and 404 otherwise.

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.

The private-key operations in ecc.c in wolfSSL before 4.4.0 do not use a constant-time modular inverse when mapping to affine coordinates, aka a "projective coordinates leak."

djangoSIGE through 1.10 (commit a6fe7e8) contains a user enumeration vulnerability in ForgotPasswordView within djangosige/apps/login/views.py that allows unauthenticated attackers to identify valid accounts by observing distinct error messages returned by the password reset endpoint. Attackers can submit arbitrary usernames or email addresses to the POST login/esqueceu/ endpoint and distinguish between existing and non-existing accounts based on observable discrepancies in the application's responses.

In BIG-IP 15.0.0, 14.1.0-14.1.0.6, 14.0.0-14.0.0.5, 13.0.0-13.1.1.5, 12.1.0-12.1.4.1, 11.5.1-11.6.4, BIG-IQ 7.0.0, 6.0.0-6.1.0,5.2.0-5.4.0, iWorkflow 2.3.0, and Enterprise Manager 3.1.1, the Configuration utility login page may not follow best security practices when handling a malicious request.

IBM Guardium Data Encryption (GDE) 5.0.0.2 behaves differently or sends different responses under different circumstances in a way that is observable to an unauthorized actor, which could facilitate username enumeration. IBM X-Force ID: 213856.

Pimcore is an open source data & experience management platform. In versions prior to 10.1.3, it is possible to enumerate usernames via the forgot password functionality. This issue is fixed in version 10.1.3. As a workaround, one may apply the available patch manually.

An issue was discovered in Symfony 4.2.0 to 4.2.11 and 4.3.0 to 4.3.7. The ability to enumerate users was possible due to different handling depending on whether the user existed when making unauthorized attempts to use the switch users functionality. This is related to symfony/security.

The Reset Password feature in Pagekit 1.0.17 gives a different response depending on whether the e-mail address of a valid user account is entered, which might make it easier for attackers to enumerate accounts.

An issue was discovered in ConnectWise Control (formerly known as ScreenConnect) 19.3.25270.7185. There is a user enumeration vulnerability, allowing an unauthenticated attacker to determine with certainty if an account exists for a given username.

The HCL Domino AppDev Pack IAM service is susceptible to a User Account Enumeration vulnerability.   During a failed login attempt a difference in messages could allow an attacker to determine if the user is valid or not.  The attacker could use this information to focus a brute force attack on valid users.

The Page Restriction WordPress (WP) – Protect WP Pages/Post plugin for WordPress is vulnerable to Sensitive Information Exposure in all versions up to, and including, 1.3.6 via the WordPress core search feature. This makes it possible for unauthenticated attackers to extract sensitive data from posts that have been restricted to higher-level roles such as administrator.

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.

In CentOS-WebPanel.com (aka CWP) CentOS Web Panel 0.9.8.846, the Login process allows attackers to check whether a username is valid by reading the HTTP response.

CyberArk Identity 21.5.131, when handling an invalid authentication attempt, sometimes reveals whether the username is valid. In certain authentication policy configurations with MFA, the API response length can be used to differentiate between a valid user and an invalid one (aka Username Enumeration). Response differentiation enables attackers to enumerate usernames of valid application users. Attackers can use this information to leverage brute-force and dictionary attacks in order to discover valid account information such as passwords.

Under certain circumstances a CCURE Portal user could enumerate user accounts in CCURE 9000 version 2.90 and prior versions.

Cap-go before 12.128.2 contains an information disclosure vulnerability in the OPTIONS /build/upload/:jobId/* endpoint that allows unauthenticated attackers to enumerate valid builder job IDs through observable response discrepancies. Attackers can probe the endpoint without authentication to distinguish valid job IDs from invalid ones and generate sustained unauthenticated traffic for resource consumption.

Capgo before 12.128.2 contains an information disclosure vulnerability in the public.invite_user_to_org RPC function that allows unauthenticated attackers to enumerate organization existence by observing distinct error responses. Attackers can call the SECURITY DEFINER function with a publishable API key to determine if an organization ID exists based on NO_ORG versus NO_RIGHTS responses, enabling tenant enumeration attacks.

GLPI 9.5.7 contains a username enumeration vulnerability in the lost password recovery mechanism that allows attackers to validate email addresses. Attackers can systematically test email addresses by submitting requests to the password reset endpoint and analyzing response differences to identify valid user accounts.

IBM Security Identity Manager 7.0.2 could allow a remote user to enumerate usernames due to a difference of responses from valid and invalid login attempts. IBM X-Force ID: 200018

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

In Bromite through 78.0.3904.130, there are adblock rules in the release APK; therefore, probing which resources are blocked and which aren't can identify the application version and defeat the User-Agent protection mechanism.

A username enumeration vulnerability exists in multiple WSO2 products when Multi-Attribute Login is enabled. In this configuration, the system returns a distinct "User does not exist" error message to the login form, regardless of the validate_username setting. This behavior allows malicious actors to determine which usernames exist in the system based on observable discrepancies in the application's responses. Exploitation of this vulnerability could aid in brute-force attacks, targeted phishing campaigns, or other social engineering techniques by confirming the validity of user identifiers within the system.

_account_forgot_password.ajax.php in MFScripts YetiShare 3.5.2 through 4.5.3 takes a different amount of time to return depending on whether an email address is configured for the account name provided. This can be used by an attacker to enumerate accounts by guessing email addresses.

In the Voatz application 2020-01-01 for Android, the amount of data transmitted during a single voter's vote depends on the different lengths of the metadata across the available voting choices, which makes it easier for remote attackers to discover this voter's choice by sniffing the network. For example, a small amount of sniffed data may indicate that a vote was cast for the candidate with the least metadata. An active man-in-the-middle attacker can leverage this behavior to disrupt voters' abilities to vote for a candidate opposed by the attacker.

Observable Timing Discrepancy in GitHub repository answerdev/answer prior to 1.0.6.

Observable Response Discrepancy in GitHub repository answerdev/answer prior to 1.0.6.

A vulnerability has been identified in Mendix Forgot Password (Mendix 7 compatible) (All versions < V3.7.1), Mendix Forgot Password (Mendix 8 compatible) (All versions < V4.1.1), Mendix Forgot Password (Mendix 9 compatible) (All versions < V5.1.1). The affected versions of the module contain an observable response discrepancy issue that could allow an attacker to retrieve sensitive information.

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.

Observable Discrepancy in GitHub repository healthchecks/healthchecks prior to v2.6.

Redmine before 4.0.9 and 4.1.x before 4.1.3 allows an attacker to learn the values of internal authentication keys by observing timing differences in string comparison operations within SysController and MailHandlerController.

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.

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.

An exposure of sensitive information vulnerability exists in TCExam <= 14.8.1. If a password reset request was made for an email address that was not registered with a user then we would be presented with an ‘unknown email’ error. If an email is given that is registered with a user then this error will not appear. A malicious actor could abuse this to enumerate the email addresses of

ManageEngine ADSelfService Plus below build 6116 contains an observable response discrepancy in the UMCP operation of the ChangePasswordAPI. This allows an unauthenticated remote attacker to determine whether a Windows domain user exists.

SPIP before 3.1.11 and 3.2 before 3.2.5 provides different error messages from the password-reminder page depending on whether an e-mail address exists, which might help attackers to enumerate subscribers.

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.

Combodo iTop is a simple, web based IT Service Management tool. Unauthenticated user can perform users enumeration, which can make it easier to bruteforce a valid account. As a fix the sentence displayed after resetting password no longer shows if the user exists or not. This fix is included in versions 2.7.11, 3.0.5, 3.1.2, and 3.2.0. Users are advised to upgrade. Users unable to upgrade may overload the dictionary entry `"UI:ResetPwd-Error-WrongLogin"` through an extension and replace it with a generic message.

On Coldcard MK1 and MK2 devices, a side channel for the row-based OLED display was found. The power consumption of each row-based display cycle depends on the number of illuminated pixels, allowing a partial recovery of display contents. For example, a hardware implant in the USB cable might be able to leverage this behavior to recover confidential secrets such as the PIN and BIP39 mnemonic. In other words, the side channel is relevant only if the attacker has enough control over the device's USB connection to make power-consumption measurements at a time when secret data is displayed. The side channel is not relevant in other circumstances, such as a stolen device that is not currently displaying secret data. On Coldcard MK1 and MK2 devices, a side channel for the row-based OLED display was found. The power consumption of each row-based display cycle depends on the number of illuminated pixels, allowing a partial recovery of display contents. For example, a hardware implant in the USB cable might be able to leverage this behavior to recover confidential secrets such as the PIN and BIP39 mnemonic. In other words, the side channel is relevant only if the attacker has enough control over the device's USB connection to make power-consumption measurements at a time when secret data is displayed. The side channel is not relevant in other circumstances, such as a stolen device that is not currently displaying secret data. NOTE: At Coinkite, we’ve already mitigated it, even though we feel strongly that it is not a legitimate issue. In our opinion, it is both unproven (might not even work) and also completely impractical—even if it could be made to work perfectly

Directus is a real-time API and App dashboard for managing SQL database content. Before 11.14.1, a timing-based user enumeration vulnerability exists in the password reset functionality. When an invalid reset_url parameter is provided, the response time differs by approximately 500ms between existing and non-existing users, enabling reliable user enumeration. This vulnerability is fixed in 11.14.1.

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