Resource exhaustion in Cometd

CVE-2025-53114

CometD is a scalable comet implementation for web messaging. In versions 5.0.0 through 5.0.22, 6.0.0 through 6.0.18, 7.0.0 through 7.0.18, and 8.0.0 through 8.0.8, bad clients that always send a fixed batch value when the server is using the acknowledgement extension may cause the unacknowledged message queue to grow indefinitely, eventually causing an `OutOfMemoryError`. Versions 5.0.23, 6.0.19, 7.0.19, and 8.0.9 patch the issue. As a workaround, disable the acknowledgement extension.

Vulnerability class: DoS (Denial of Service)

Published · last modified .

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.007 (50.6th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 51st percentile — 50.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2025-53114: held from 0.007 to 0.007.

EPSS over last 30 days · oldest: 0.007 · newest: 0.007 · change: 0.000

Affected products

  • Cometd — versions >= 5.0.0, < 5.0.23, >= 6.0.0, < 6.0.19, >= 7.0.0, < 7.0.19

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2025-53114?
CVE-2025-53114 is a high-severity vulnerability in Cometd, classified under Uncontrolled Resource Consumption. CVSS score: 7.5/10. Published 2026-06-18.
How severe is CVE-2025-53114?
High severity. CVSS v3 base score is 7.5 out of 10.