CVE-2025-46171
MediumCVSS 5.4Exploitation Probability (EPSS)
Low risk15th percentile - higher than 15% of all known CVEs
Summary
A vulnerability in vBulletin 3.8.7 allows a DoS attack via the misc.php?do=buddylist endpoint. An authenticated user with an excessively large buddy list can cause excessive memory consumption, exhausting system resources and crashing the forum.
Risk Assessment
The risk is that an authenticated user can intentionally overload the server, leading to forum unavailability for all users and potential data loss in case of an unexpected shutdown.
Recommendation
It is recommended to limit the maximum buddy list size in vBulletin configuration or apply a security patch from the vendor if available. Also monitor memory usage of the forum process.
Other vulnerabilities in vBulletin
See all- CVE-2017-7569High
In vBulletin versions before 5.3.0, remote attackers can bypass the CVE-2016-6483 patch and conduct SSRF attacks by leveraging the behavior of the PHP parse_url function.
- CVE-2016-6483High
The media-file upload feature in vBulletin before certain versions allows remote attackers to conduct SSRF attacks via a crafted URL, resulting in a Redirection HTTP status code.
- CVE-2026-61511Critical
vBulletin versions 5.x through 5.7.5 and 6.x through 6.2.1 contain an eval injection vulnerability in the vB5_Template_Runtime::runMaths() method, allowing unauthenticated remote attackers to execute arbitrary PHP code via crafted pagenav[pagenumber] parameter.
- CVE-2017-17672Critical
In vBulletin versions up to 5.3.x, there is an unauthenticated deserialization vulnerability that can lead to arbitrary file deletion and, under certain circumstances, code execution. This issue arises from the unsafe usage of PHP's unserialize() function in the cacheTemplates() method of the vB_Library_Template class, which is publicly exposed.
- CVE-2017-17671Critical
vBulletin versions up to 5.3.x on Windows allows remote PHP code execution due to the accessibility of a require_once call with an unauthenticated request that can include directory traversal sequences to specify an arbitrary pathname. The blocking of ../ traversal does not apply to ..\, allowing for exploitation of this vulnerability.
- CVE-2026-9357Low
A vulnerability in vBulletin 6.x in an unknown function of the Login component leads to cross-site scripting (XSS). The attack can be initiated remotely. The exploit has been made public.
Original NVD description (English source)
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.