CVE-2025-51846 CryptPad unbounded WebSocket frame flood

High 8.7 Published 30 Apr 2026 Updated 30 Apr 2026

A remote unauthenticated attacker can degrade or deny service to all users of a CryptPad instance via unbounded WebSocket frame floods.

Exploited in the wild: Not known
Login needed: Not needed
Attackable: Over the internet
Victim action needed: Not needed
Fix: None listed

What is CVE-2025-51846?

CVE-2025-51846 is a high-severity denial of service vulnerability in CryptPad, published on 30 Apr 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

CryptPad 2025.3.1 allows unbounded WebSocket frame flood. A remote, unauthenticated attacker can significantly degrade or deny service for all users of a CryptPad instance. Fixed in 2026.2.2.

Weakness: CWE-770

Which versions are affected by CVE-2025-51846?

It affects 1 product.

Products include Xwiki Cryptpad.

How do I fix CVE-2025-51846?

No fix has been published for CVE-2025-51846 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-2025-51846 being exploited?

There is no known exploitation of CVE-2025-51846 in the wild and no public exploit code.

Public exploit code: 1 proofs of concept on GitHub.

Sources

Also known as GHSA-jmrh-f3j8-q3c4.