CVE-2025-53114
Acknowledgement extension out of memory
Description
### Impact Bad clients that always send a fixed batch value while the server is using the acknowledgement extension can cause the unacknowledged message queue to grow indefinitely, eventually resulting in an OutOfMemoryError. Such bad clients would always send: ```json { "channel": "/meta/connect", ... "ext": { "ack": 1 } } ``` The server would never clear the unacknowledged message queue, and one bad client can cause a server outage. ### Patches 5.0.x - https://github.com/cometd/cometd/pull/2168 6.0.x - https://github.com/cometd/cometd/pull/2169 8.0.x - https://github.com/cometd/cometd/pull/2118 ### Workarounds Disable the acknowledgement extension. ### Resources https://github.com/cometd/cometd/discussions/2116 https://github.com/cometd/cometd/issues/2117
How to fix CVE-2025-53114
To remediate CVE-2025-53114, upgrade the affected package to a fixed version below.
- —upgrade to 5.0.23 or later
Is CVE-2025-53114 being exploited?
No exploitation signal available. Neither CISA KEV nor a current EPSS score has been published for CVE-2025-53114.
Affected packages (1)
- >= 5.0.0, < 5.0.23
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 3.1 | HIGH7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |