In veilid-core in Veilid before 0.3.4, the protocol's ping function can be misused in a way that decreases the effectiveness of safety and private routes.

IBM TXSeries for Multiplatforms 10.1 could allow an attacker to determine valid usernames due to an observable timing discrepancy which could be used in further attacks against the system.

In the Twilio Authy API, accessed by Authy Android before 25.1.0 and Authy iOS before 26.1.0, an unauthenticated endpoint provided access to certain phone-number data, as exploited in the wild in June 2024. Specifically, the endpoint accepted a stream of requests containing phone numbers, and responded with information about whether each phone number was registered with Authy. (Authy accounts were not compromised, however.)

Matrix Tafnit v8 - CWE-204: Observable Response Discrepancy

Shenzhen Guoxin Synthesis image system before 8.3.0 allows username enumeration because of the response discrepancy of incorrect versus error.

In Splunk Enterprise versions below 9.2.2, 9.1.5, and 9.0.10 and Splunk Cloud Platform versions below 9.1.2312.109, an attacker could determine whether or not another user exists on the instance by deciphering the error response that they would likely receive from the instance when they attempt to log in. This disclosure could then lead to additional brute-force password-guessing attacks. This vulnerability would require that the Splunk platform instance uses the Security Assertion Markup Language (SAML) authentication scheme.

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.

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 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.

User enumeration vulnerability in ORDAT FOSS-Online before v2.24.01 allows attackers to determine if an account exists in the application by comparing the server responses of the forgot password functionality.

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.

_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.

An email address enumeration vulnerability exists in the password reset function of Rocket.Chat through 3.9.1.

All CODESYS Visualization versions before V4.2.0.0 generate a login dialog vulnerable to information exposure allowing a remote, unauthenticated attacker to enumerate valid users.

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.

A vulnerability in Qlik Sense Enterprise on Windows could allow an remote attacker to enumerate domain user accounts. An attacker could exploit this vulnerability by sending authentication requests to an affected system. A successful exploit could allow the attacker to compare the response time that are returned by the affected system to determine which accounts are valid user accounts. Affected systems are only vulnerable if they have LDAP configured. The affected URI is /internal_forms_authentication/ the response time of the form is longer if the supplied user does not exists and shorter if the user exists.

In CentOS-WebPanel.com (aka CWP) CentOS Web Panel 0.9.8.848, the Login process allows attackers to check whether a username is valid by comparing response times.

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.

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.

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.

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

Crypto++ (aka Cryptopp) 8.6.0 and earlier contains a timing leakage in MakePublicKey(). There is a clear correlation between execution time and private key length, which may cause disclosure of the length information of the private key. This might allow attackers to conduct timing attacks. NOTE: this report is disputed by the vendor and multiple third parties. The execution-time differences are intentional. A user may make a choice of a longer key as a tradeoff between strength and performance. In making this choice, the amount of information leaked to an adversary is of infinitesimal value

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.

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.

Citrix XenApp 6.5, when 2FA is enabled, allows a remote unauthenticated attacker to ascertain whether a user exists on the server, because the 2FA error page only occurs after a valid username is entered. NOTE: This vulnerability only affects products that are no longer supported by the maintainer

An issue was discovered in Aviatrix Controller before 5.4.1204. There is a Observable Response Discrepancy from the API, which makes it easier to perform user enumeration via brute force.

When supplied with a random MAC address, Snap One OvrC cloud servers will return information about the device. The MAC address of devices can be enumerated in an attack and the OvrC cloud will disclose their information.

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.

Umbraco is an ASP.NET content management system. Umbraco 10 prior to 10.8.4 with access to the native login screen is vulnerable to a possible user enumeration attack. This issue was fixed in version 10.8.5. As a workaround, one may disable the native login screen by exclusively using external logins.

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.

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.

goauthentik is an open-source Identity Provider. In affected versions using a recovery flow with an identification stage an attacker is able to determine if a username exists. Only setups configured with a recovery flow are impacted by this. Anyone with a user account on a system with the recovery flow described above is susceptible to having their username/email revealed as existing. An attacker can easily enumerate and check users' existence using the recovery flow, as a clear message is shown when a user doesn't exist. Depending on configuration this can either be done by username, email, or both. This issue has been addressed in versions 2023.5.6 and 2023.6.2. Users are advised to upgrade. There are no known workarounds for this issue.

IBM CICS TX Advanced 10.1 could disclose sensitive information to a remote attacker due to observable discrepancy in HTTP responses. IBM X-Force ID: 260814.

Username enumeration is possible through Bypassing CAPTCHA in On-premise SureMDM Solution on Windows deployment allows attacker to enumerate local user information via error message. This issue affects SureMDM On-premise: 6.31 and below version

The commit 3730880 (April 2023) and v.0.9-beta1 of gugoan Economizzer has a user enumeration vulnerability in the login and forgot password functionalities. The app reacts differently when a user or email address is valid, and when it's not. This may allow an attacker to determine whether a user or email address is valid, or brute force valid usernames and email addresses.

An issue was discovered in eGroupWare 17.1.20190111. A User Enumeration vulnerability exists under calendar/freebusy.php, which allows unauthenticated remote attackers to enumerate the users of web applications based on server response.

Tadiran Telecom Aeonix - CWE-204: Observable Response Discrepancy

The login functionality of the web server in affected devices does not normalize the response times of login attempts. An unauthenticated remote attacker could exploit this side-channel information to distinguish between valid and invalid usernames.

An issue was discovered in the ProofreadPage (aka Proofread Page) extension for MediaWiki through 1.39.3. In includes/Page/PageContentHandler.php and includes/Page/PageDisplayHandler.php, hidden users can be exposed via public interfaces.

IBM Aspera Faspex 5.0.0 through 5.0.10 could disclose sensitive username information due to an observable response discrepancy.

Zabbix through 4.4.0alpha1 allows User Enumeration. With login requests, it is possible to enumerate application usernames based on the variability of server responses (e.g., the "Login name or password is incorrect" and "No permissions for system access" messages, or just blocking for a number of seconds). This affects both api_jsonrpc.php and index.php.

Observable Response Discrepancy in the SICK ICR890-4 could allow a remote attacker to identify valid usernames for the FTP server from the response given during a failed login attempt.

A vulnerability classified as problematic has been found in Rotem Dynamics Rotem CRM up to 20230729. This affects an unknown part of the file /LandingPages/api/otp/send?id=[ID][ampersand]method=sms of the component OTP URI Interface. The manipulation leads to information exposure through discrepancy. It is possible to initiate the attack remotely. The identifier VDB-233253 was assigned to this vulnerability. NOTE: The vendor was contacted early about this disclosure but did not respond in any way.

AMI BMC contains a vulnerability in the IPMI handler, where an unauthorized attacker can use certain oracles to guess a valid username, which may lead to information disclosure.

HashiCorp's Vault and Vault Enterprise are vulnerable to user enumeration when using the LDAP auth method. An attacker may submit requests of existent and non-existent LDAP users and observe the response from Vault to check if the account is valid on the LDAP server. This vulnerability is fixed in Vault 1.14.1 and 1.13.5.

emoncms v11 and later was discovered to contain an information disclosure vulnerability which allows attackers to obtain the web directory path and other information leaked by the server via a crafted web request.

TN-5900 Series version 3.3 and prior versions is vulnearble to user enumeration vulnerability. The vulnerability may allow a remote attacker to determine whether a user is valid during password recovery through the web login page and enable a brute force attack with valid users.

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

User enumeration vulnerability in Password Recovery plugin 1.2 version for Roundcube, which could allow a remote attacker to create a test script against the password recovery function to enumerate all users in the database.

User enumeration vulnerability in Liferay Portal 7.2.0 through 7.4.3.26, and older unsupported versions, and Liferay DXP 7.4 before update 27, 7.3 before update 8, 7.2 before fix pack 20, and older unsupported versions allows remote attackers to determine if an account exist in the application by comparing the request's response time.