GHSA-CQGJ-H8VF-4W59

Vulnerability from github – Published: 2026-06-10 16:46 – Updated: 2026-06-10 16:46
VLAI
Summary
Acknowledgement extension out of memory
Details

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:

{
  "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

Severity
7.5 (High)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Show details on source website
To clipboard 

{
  "affected": [
    {
      "database_specific": {
        "last_known_affected_version_range": "\u003c= 5.0.22"
      },
      "package": {
        "ecosystem": "Maven",
        "name": "org.cometd.java:cometd-java-server-common"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "5.0.0"
            },
            {
              "fixed": "5.0.23"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "database_specific": {
        "last_known_affected_version_range": "\u003c= 6.0.18"
      },
      "package": {
        "ecosystem": "Maven",
        "name": "org.cometd.java:cometd-java-server-common"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "6.0.0"
            },
            {
              "fixed": "6.0.19"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "database_specific": {
        "last_known_affected_version_range": "\u003c= 7.0.18"
      },
      "package": {
        "ecosystem": "Maven",
        "name": "org.cometd.java:cometd-java-server-common"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "7.0.0"
            },
            {
              "fixed": "7.0.19"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "database_specific": {
        "last_known_affected_version_range": "\u003c= 8.0.8"
      },
      "package": {
        "ecosystem": "Maven",
        "name": "org.cometd.java:cometd-java-server-common"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "8.0.0"
            },
            {
              "fixed": "8.0.9"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2025-53114"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-400"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-06-10T16:46:28Z",
    "nvd_published_at": null,
    "severity": "HIGH"
  },
  "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",
  "id": "GHSA-cqgj-h8vf-4w59",
  "modified": "2026-06-10T16:46:28Z",
  "published": "2026-06-10T16:46:28Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/cometd/cometd/security/advisories/GHSA-cqgj-h8vf-4w59"
    },
    {
      "type": "WEB",
      "url": "https://github.com/cometd/cometd/issues/2117"
    },
    {
      "type": "WEB",
      "url": "https://github.com/cometd/cometd/pull/2118"
    },
    {
      "type": "WEB",
      "url": "https://github.com/cometd/cometd/pull/2168"
    },
    {
      "type": "WEB",
      "url": "https://github.com/cometd/cometd/pull/2169"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/cometd/cometd"
    },
    {
      "type": "WEB",
      "url": "https://github.com/cometd/cometd/discussions/2116"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Acknowledgement extension out of memory"
}


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Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

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Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
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  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
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  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


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