CVE-2026-61387 Denial of service in Eclipse Milo

Medium 6.9 Published 4 Aug 2026 Updated 4 Aug 2026

Unauthenticated remote attackers can exhaust monitored-item quotas via deep nesting, preventing new item creation until server restart.

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-2026-61387?

CVE-2026-61387 is a medium-severity denial of service vulnerability in Eclipse Milo, published on 4 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

In Eclipse Milo versions 1.0.0 through 1.1.4, monitored-item quota accounting is not exception-safe: if item creation fails with an unchecked error, the server-global reservation is not restored. Deeply nested PubSub ExtensionObjects in a `CreateMonitoredItems` event filter can trigger a `StackOverflowError` during decoding, allowing an unauthenticated remote client to exhaust a finite global monitored-item quota and prevent all clients from creating new monitored items until restart. Existing monitored items and other server functions remain unaffected.

Weakness: CWE-772, CWE-460, CWE-400

Which versions are affected by CVE-2026-61387?

It affects 1 product.

Products include Eclipse Milo.

How do I fix CVE-2026-61387?

No fix has been published for CVE-2026-61387 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-2026-61387 being exploited?

There is no known exploitation of CVE-2026-61387 in the wild and no public exploit code.

Sources

Also known as GHSA-54cr-fx8f-gpc5.