vBulletin 5.x through 5.7.5 and 6.x through 6.2.1 contains an eval injection vulnerability in the vB5TemplateRuntime::runMaths() method within the template runtime that allows unauthenticated remote attackers to execute arbitrary PHP code by supplying crafted input through the pagenav[pagenumber] parameter. Attackers can exploit the insufficiently restrictive regex filter by using phpfuck-style encoding with permitted characters to inject and execute arbitrary PHP code via the unauthenticated ajax/render template route without any authentication.

CVE-2026-61511 - a critical vulnerability in vBulletin that allows an unauthenticated attacker to execute arbitrary code on a remote server.

A vulnerability was found in vBulletin 6.x. This impacts an unknown function of the component Login. Performing a manipulation results in cross site scripting. It is possible to initiate the attack remotely. The exploit has been made public and could be used. VulDB is withholding an extended redistribution of exploit details to prevent simplified exploitation. The vendor was contacted early about this disclosure but did not respond in any way.

vBulletin 3.8.7 is vulnerable to a denial-of-service condition via the misc.php?do=buddylist endpoint. If an authenticated user has a sufficiently large buddy list, processing the list can consume excessive memory, exhausting system resources and crashing the forum.

vBulletin 5.5.4 through 5.6.2 allows remote command execution via crafted subWidgets data in an ajax/render/widgettabbedcontainertabpanel request. NOTE: this issue exists because of an incomplete fix for CVE-2019-16759.

vBulletin 5.x through 5.5.4 allows remote command execution via the widgetConfig[code] parameter in an ajax/render/widgetphp routestring request.

vBulletin 3.x.x and 4.2.x through 4.2.5 has an open redirect via the redirector.php url parameter.

In vBulletin before 5.3.0, remote attackers can bypass the CVE-2016-6483 patch and conduct SSRF attacks by leveraging the behavior of the PHP parseurl function, aka VBV-17037.

Multiple cross-site scripting (XSS) vulnerabilities in vBulletin 5.1.1 Alpha 9 allow remote attackers to inject arbitrary web script or HTML via (1) the PATHINFO to privatemessage/new/, (2) the folderid parameter to a private message in privatemessage/view, (3) a fragment indicator to /help, or (4) the view parameter to a topic, as demonstrated by a request to forum/anunturi-importante/rst-power/67030-rst-admin-restore.

The install/upgrade.php scripts in vBulletin 4.1 and 5 allow remote attackers to create administrative accounts via the customerid, htmldata[password], htmldata[confirmpassword], and htmldata[email] parameters, as exploited in the wild in October 2013.

SQL injection vulnerability in admincp/admincalendar.php in vBulletin 3.7.3.pl1 allows remote authenticated administrators to execute arbitrary SQL commands via the holidayinfo[recurring] parameter, a different vector than CVE-2005-3022.

Multiple SQL injection vulnerabilities in vBulletin 3.7.4 allow remote authenticated administrators to execute arbitrary SQL commands via the (1) answer parameter to admincp/verify.php, (2) extension parameter in an edit action to admincp/attachmentpermission.php, and the (3) iperm parameter to admincp/image.php.

Directory traversal vulnerability in vbseo.php in Crawlability vBSEO plugin 3.1.0 for vBulletin allows remote attackers to include and execute arbitrary local files via directory traversal sequences in the vbseourl parameter.

Unspecified vulnerability in the MAPI in vBulletin Suite 4.1.2 through 4.1.12, Forum 4.1.2 through 4.1.12, and the MAPI plugin 1.4.3 for vBulletin 3.x has unknown impact and attack vectors.

Cross-site request forgery (CSRF) vulnerability in the Moderator Control Panel in vBulletin 4.2.2 allows remote attackers to hijack the authentication of administrators for requests that (1) ban a user via the username parameter in a dobanuser action to modcp/banning.php or (2) unban a user, (3) modify user profiles, edit a (4) post or (5) topic, or approve a (6) post or (7) topic via unspecified vectors.

Cross-site scripting (XSS) vulnerability in vBulletin 3.5.4, 3.6.0, 3.6.7, 3.8.7, 4.2.2, 5.0.5, and 5.1.3.

functionsvbseohook.php in the VBSEO module for vBulletin allows remote authenticated users to execute arbitrary code via the HTTP Referer header to visitormessage.php.

In vBulletin through 5.3.x, there is an unauthenticated deserialization vulnerability that leads to arbitrary file deletion and, under certain circumstances, code execution, because of unsafe usage of PHP's unserialize() in vBLibraryTemplate's cacheTemplates() function, which is a publicly exposed API. This is exploited with the templateidlist parameter to ajax/api/template/cacheTemplates.

vBulletin through 5.3.x on Windows allows remote PHP code execution because a requireonce call is reachable with an unauthenticated request that can include directory traversal sequences to specify an arbitrary pathname, and because ../ traversal is blocked but ..\ traversal is not blocked. For example, an attacker can make an invalid HTTP request containing PHP code, and then make an index.php?routestring= request with enough instances of ".." to reach an Apache HTTP Server log file.