{"id":"CVE-2025-53114","aliases":["GHSA-cqgj-h8vf-4w59"],"url":"https://o3.security/vulnerability/CVE-2025-53114","summary":"CometD has acknowledgement extension out of memory","details":"### Impact\nBad 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.\n\nSuch bad clients would always send:\n\n```json\n{\n  \"channel\": \"/meta/connect\",\n  ...\n  \"ext\": { \"ack\": 1 }\n}\n```\n\nThe server would never clear the unacknowledged message queue, and one bad client can cause a server outage.\n\n### Patches\n5.0.x - https://github.com/cometd/cometd/pull/2168\n6.0.x - https://github.com/cometd/cometd/pull/2169\n8.0.x - https://github.com/cometd/cometd/pull/2118\n\n### Workarounds\nDisable the acknowledgement extension.\n\n### Resources\nhttps://github.com/cometd/cometd/discussions/2116\nhttps://github.com/cometd/cometd/issues/2117","published":"2026-06-18T16:25:47.388Z","modified":"2026-08-12T03:51:20.800088047Z","cvss":{"score":7.5,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"},"epss":{"score":0.00684,"percentile":0.49797,"asOf":"2026-08-24"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"Maven","name":"org.cometd.java:cometd-java-server-common","fixedVersion":"5.0.23"},{"ecosystem":"Maven","name":"org.cometd.java:cometd-java-server-common","fixedVersion":"6.0.19"},{"ecosystem":"Maven","name":"org.cometd.java:cometd-java-server-common","fixedVersion":"7.0.19"},{"ecosystem":"Maven","name":"org.cometd.java:cometd-java-server-common","fixedVersion":"8.0.9"}],"fix":{"url":"https://github.com/cometd/cometd/pull/2118","label":"cometd/cometd#2118"},"references":[{"type":"WEB","url":"https://github.com/cometd/cometd/discussions/2116"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/53xxx/CVE-2025-53114.json"},{"type":"ADVISORY","url":"https://github.com/cometd/cometd/security/advisories/GHSA-cqgj-h8vf-4w59"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2025-53114"},{"type":"REPORT","url":"https://github.com/cometd/cometd/issues/2117"},{"type":"FIX","url":"https://github.com/cometd/cometd/pull/2118"},{"type":"FIX","url":"https://github.com/cometd/cometd/pull/2168"},{"type":"FIX","url":"https://github.com/cometd/cometd/pull/2169"},{"type":"PACKAGE","url":"https://github.com/cometd/cometd"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-12T03:51:20.800088047Z"}}