CVE-2026-73561 Hub: Unauthenticated WebSocket RPC Waiter Resource Exhaustion
Unauthenticated WebSocket connections cause resource exhaustion via uncancelled timers, leading to server unavailability in the Hub library.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-73561?
CVE-2026-73561 is a high-severity denial of service vulnerability in anephenix hub, published on 13 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
Hub is a Node.js WebSocket server and client with added features. Prior to 0.2.16, every incoming unauthenticated WebSocket connection triggers loadDefaultConnectionEventListeners to call requestClientId, which calls rpc.send for the get-client-id action and pushes a request into RPC.requests. The RPC.waitForReply function starts a setInterval polling loop every 10 milliseconds that is cleared only after a matching reply; if the client remains silent and closes, the timer and pending request stay allocated because the socket close path does not cancel them. Repeated connections therefore cause unbounded timers and heap entries, exhausting CPU and memory and making the server unavailable. This issue is fixed in version 0.2.16.
Weakness: CWE-400
Which versions are affected by CVE-2026-73561?
2 open source packages ship an affected version, including @anephenix/hub.
| Package | Affected | Fixed in |
|---|---|---|
@anephenix/hub npm | All versions | 0.2.16 |
@anephenix/hub npm | All versions | 0.2.16 |
How do I fix CVE-2026-73561?
Upgrade @anephenix/hub to 0.2.16 or later.
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-2026-73561 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-73561 exists.
Sources
Also known as GHSA-g5vv-q72c-7j78.