CVE-2026-102599

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Source
https://cve.org/CVERecord?id=CVE-2026-102599
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-102599.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2026-102599
Aliases
Downstream
CGA (28)
MINI (1)
Published
2026-10-13T19:05:10Z
Modified
2026-10-28T02:30:51Z
Severity
  • 7.5 (High) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H CVSS Calculator
Summary
Socket.IO: Engine.IO Protocol Revision Mismatch DoS
Details

Socket.IO enables bidirectional and low-latency communication for every platform. From Engine.IO 6.6.0 until 6.6.10, a transport upgrade can independently derive an Engine.IO protocol revision from the upgrade request instead of enforcing the revision stored on the existing session. A malicious client can establish a valid session and send an upgrade request with a different or omitted EIO query parameter, attaching a transport with incompatible parser and heartbeat behavior. A crafted heartbeat packet can then trigger an uncaught exception and terminate the Node.js process, including when Engine.IO v3 compatibility is disabled because an omitted EIO value is interpreted as revision 3 on the affected path. This issue is fixed in Engine.IO 6.6.10.

Database specific 
{
    "cna_assigner": "GitHub_M",
    "cwe_ids": [
        "CWE-248"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/102xxx/CVE-2026-102599.json"
}
References

Affected packages

Git / github.com/socketio/socket.io

Affected ranges

Type
GIT
Repo
https://github.com/socketio/socket.io
Events
Introduced
791aa58f4c0a003335a945fdd704cb910bd35970
Fixed
64066c367386b3eb96677479a8978d6a8230c5ee
Fixed
86db1fc3db2cd315a065d64c4e48918ccf9b4729
Database specific
Show details 
{
    "extracted_events": [
        {
            "range": [
                {
                    "introduced": "6.6.0"
                },
                {
                    "fixed": "6.6.10"
                }
            ],
            "source": "AFFECTED_FIELD",
            "strategy": "StringRangeExpression"
        },
        {
            "range": [
                {
                    "fixed": "86db1fc3db2cd315a065d64c4e48918ccf9b4729"
                }
            ],
            "source": "REFERENCES_COMMIT"
        },
        {
            "original_tag": "engine.io@6.6.10",
            "range": [
                {
                    "fixed": "64066c367386b3eb96677479a8978d6a8230c5ee"
                }
            ],
            "source": "REFERENCES_TAG"
        }
    ]
}

Database specific

source 
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-102599.json"