CVE-2026-61387

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.

References

• https://github.com/eclipse-milo/milo/commit/587e35669f519b2d7f6d850a5f86ee5a76c3a2c5
• https://github.com/eclipse-milo/milo/commit/5f3f6da2a5ea80682e1da7c58f7a1870b09d2b43
• https://gitlab.eclipse.org/security/cve-assignment/-/work_items/182
• https://gitlab.eclipse.org/security/vulnerability-reports/-/work_items/598