{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2026-62949",
        "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "state": "PUBLISHED",
        "assignerShortName": "GitHub_M",
        "dateReserved": "2026-07-14T22:32:17.731Z",
        "datePublished": "2026-09-16T20:00:46.657Z",
        "dateUpdated": "2026-09-17T15:01:48.863Z"
    },
    "containers": {
        "cna": {
            "title": "AsyncSSH: asyncio event-loop freeze via SSH maximum packet size = 0 in SSH_MSG_CHANNEL_OPEN / OPEN_CONFIRMATION",
            "problemTypes": [
                {
                    "descriptions": [
                        {
                            "cweId": "CWE-835",
                            "lang": "en",
                            "description": "CWE-835: Loop with Unreachable Exit Condition ('Infinite Loop')",
                            "type": "CWE"
                        }
                    ]
                }
            ],
            "metrics": [
                {
                    "cvssV3_1": {
                        "attackComplexity": "LOW",
                        "attackVector": "NETWORK",
                        "availabilityImpact": "HIGH",
                        "baseScore": 6.5,
                        "baseSeverity": "MEDIUM",
                        "confidentialityImpact": "NONE",
                        "integrityImpact": "NONE",
                        "privilegesRequired": "LOW",
                        "scope": "UNCHANGED",
                        "userInteraction": "NONE",
                        "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
                        "version": "3.1"
                    }
                }
            ],
            "references": [
                {
                    "name": "https://github.com/ronf/asyncssh/security/advisories/GHSA-rw4j-r22c-9gc3",
                    "tags": [
                        "x_refsource_CONFIRM"
                    ],
                    "url": "https://github.com/ronf/asyncssh/security/advisories/GHSA-rw4j-r22c-9gc3"
                },
                {
                    "name": "https://github.com/ronf/asyncssh/commit/756cbae5350789ce9735f15f704bae9b5a3608b8",
                    "tags": [
                        "x_refsource_MISC"
                    ],
                    "url": "https://github.com/ronf/asyncssh/commit/756cbae5350789ce9735f15f704bae9b5a3608b8"
                },
                {
                    "name": "https://github.com/ronf/asyncssh/commit/9c354270c009285525e126721e8ed5fbed1f8a67",
                    "tags": [
                        "x_refsource_MISC"
                    ],
                    "url": "https://github.com/ronf/asyncssh/commit/9c354270c009285525e126721e8ed5fbed1f8a67"
                },
                {
                    "name": "https://github.com/ronf/asyncssh/releases/tag/v2.24.0",
                    "tags": [
                        "x_refsource_MISC"
                    ],
                    "url": "https://github.com/ronf/asyncssh/releases/tag/v2.24.0"
                }
            ],
            "affected": [
                {
                    "vendor": "ronf",
                    "product": "asyncssh",
                    "versions": [
                        {
                            "version": "< 2.24.0",
                            "status": "affected"
                        }
                    ]
                }
            ],
            "providerMetadata": {
                "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
                "shortName": "GitHub_M",
                "dateUpdated": "2026-09-16T20:00:46.657Z"
            },
            "descriptions": [
                {
                    "lang": "en",
                    "value": "AsyncSSH is a Python package which provides an asynchronous client and server implementation of the SSHv2 protocol on top of the Python asyncio framework. Prior to 2.24.0, _process_channel_open and _process_channel_open_confirmation in asyncssh/connection.py accept a peer-supplied send_pktsize value of zero. When channel data reaches SSHChannel._flush_send_buf in asyncssh/channel.py, the zero value causes each loop iteration to slice and remove zero bytes without reducing the send window, leaving the synchronous loop permanently true with no await point. A malicious SSH server can trigger the client path through SSH_MSG_CHANNEL_OPEN_CONFIRMATION before the first channel write, while an authenticated client can trigger the server path through SSH_MSG_CHANNEL_OPEN and freeze every current and future connection handled by the process. This vulnerability is fixed in 2.24.0."
                }
            ],
            "source": {
                "advisory": "GHSA-rw4j-r22c-9gc3",
                "discovery": "UNKNOWN"
            }
        },
        "adp": [
            {
                "metrics": [
                    {
                        "other": {
                            "type": "ssvc",
                            "content": {
                                "timestamp": "2026-09-17T15:01:41.382412Z",
                                "id": "CVE-2026-62949",
                                "options": [
                                    {
                                        "Exploitation": "none"
                                    },
                                    {
                                        "Automatable": "no"
                                    },
                                    {
                                        "Technical Impact": "partial"
                                    }
                                ],
                                "role": "CISA Coordinator",
                                "version": "2.0.3"
                            }
                        }
                    }
                ],
                "title": "CISA ADP Vulnrichment",
                "providerMetadata": {
                    "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
                    "shortName": "CISA-ADP",
                    "dateUpdated": "2026-09-17T15:01:48.863Z"
                }
            }
        ]
    }
}