CVE-2025-46171 Denial of service in n/a
An authenticated user can crash the vBulletin forum by triggering excessive memory consumption through a large buddy list.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2025-46171?
CVE-2025-46171 is a medium-severity denial of service vulnerability in Vbulletin Vbulletin, published on 23 Jul 2025. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Official description
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.
Weakness: CWE-400
Which versions are affected by CVE-2025-46171?
It affects 1 product.
Products include Vbulletin Vbulletin.
How do I fix CVE-2025-46171?
No fix has been published for CVE-2025-46171 yet. Limit exposure of the affected software until one is available.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2025-46171 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2025-46171 exists.
Public exploit code: 1 proofs of concept on GitHub.
Other vulnerabilities in Vbulletin Vbulletin
- CVE-2020-17496 vBulletin PHP Module Remote Code Execution
- CVE-2019-16759 vBulletin PHP Module Remote Code Execution
- CVE-2025-48827 vBulletin 5.0.0 through 5.7.5 and 6.0.0 through 6.0.3 allows unauthenticated users to invoke protected API controllers' methods when running
- CVE-2023-25135 Deserialization in n/a
- CVE-2020-7373 Code injection in n/a
Sources
Also known as GHSA-q9rx-45gj-g3f5.