{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2026-40194",
        "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "state": "PUBLISHED",
        "assignerShortName": "GitHub_M",
        "dateReserved": "2026-04-09T20:59:17.620Z",
        "datePublished": "2026-04-10T20:24:06.696Z",
        "dateUpdated": "2026-05-08T15:18:43.231Z"
    },
    "containers": {
        "cna": {
            "title": "phpseclib has a variable-time HMAC comparison in SSH2::get_binary_packet() using != instead of hash_equals()",
            "problemTypes": [
                {
                    "descriptions": [
                        {
                            "cweId": "CWE-208",
                            "lang": "en",
                            "description": "CWE-208: Observable Timing Discrepancy",
                            "type": "CWE"
                        }
                    ]
                }
            ],
            "metrics": [
                {
                    "cvssV3_1": {
                        "attackComplexity": "HIGH",
                        "attackVector": "NETWORK",
                        "availabilityImpact": "NONE",
                        "baseScore": 3.7,
                        "baseSeverity": "LOW",
                        "confidentialityImpact": "LOW",
                        "integrityImpact": "NONE",
                        "privilegesRequired": "NONE",
                        "scope": "UNCHANGED",
                        "userInteraction": "NONE",
                        "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N",
                        "version": "3.1"
                    }
                }
            ],
            "references": [
                {
                    "name": "https://github.com/phpseclib/phpseclib/security/advisories/GHSA-r854-jrxh-36qx",
                    "tags": [
                        "x_refsource_CONFIRM"
                    ],
                    "url": "https://github.com/phpseclib/phpseclib/security/advisories/GHSA-r854-jrxh-36qx"
                },
                {
                    "name": "https://github.com/phpseclib/phpseclib/commit/ffe48b6b1b1af6963327f0a5330e3aa004a194ac",
                    "tags": [
                        "x_refsource_MISC"
                    ],
                    "url": "https://github.com/phpseclib/phpseclib/commit/ffe48b6b1b1af6963327f0a5330e3aa004a194ac"
                },
                {
                    "name": "https://github.com/phpseclib/phpseclib/releases/tag/1.0.28",
                    "tags": [
                        "x_refsource_MISC"
                    ],
                    "url": "https://github.com/phpseclib/phpseclib/releases/tag/1.0.28"
                },
                {
                    "name": "https://github.com/phpseclib/phpseclib/releases/tag/2.0.53",
                    "tags": [
                        "x_refsource_MISC"
                    ],
                    "url": "https://github.com/phpseclib/phpseclib/releases/tag/2.0.53"
                },
                {
                    "name": "https://github.com/phpseclib/phpseclib/releases/tag/3.0.51",
                    "tags": [
                        "x_refsource_MISC"
                    ],
                    "url": "https://github.com/phpseclib/phpseclib/releases/tag/3.0.51"
                }
            ],
            "affected": [
                {
                    "vendor": "phpseclib",
                    "product": "phpseclib",
                    "versions": [
                        {
                            "version": ">= 0.1.1, < 1.0.28",
                            "status": "affected"
                        },
                        {
                            "version": ">= 2.0.0, < 2.0.53",
                            "status": "affected"
                        },
                        {
                            "version": ">= 3.0.0, < 3.0.51",
                            "status": "affected"
                        }
                    ]
                }
            ],
            "providerMetadata": {
                "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
                "shortName": "GitHub_M",
                "dateUpdated": "2026-05-08T15:18:43.231Z"
            },
            "descriptions": [
                {
                    "lang": "en",
                    "value": "phpseclib is a PHP secure communications library. Starting in 0.1.1 and prior to 3.0.51, 2.0.53, and 1.0.28, phpseclib\\Net\\SSH2::get_binary_packet() uses PHP's != operator to compare a received SSH packet HMAC against the locally computed HMAC. != on equal-length binary strings in PHP uses memcmp(), which short-circuits on the first differing byte. This is a real variable-time comparison (CWE-208), proven by scaling benchmarks. This vulnerability is fixed in 3.0.51, 2.0.53, and 1.0.28."
                }
            ],
            "source": {
                "advisory": "GHSA-r854-jrxh-36qx",
                "discovery": "UNKNOWN"
            }
        },
        "adp": [
            {
                "references": [
                    {
                        "url": "https://github.com/phpseclib/phpseclib/security/advisories/GHSA-r854-jrxh-36qx",
                        "tags": [
                            "exploit"
                        ]
                    }
                ],
                "metrics": [
                    {
                        "other": {
                            "type": "ssvc",
                            "content": {
                                "timestamp": "2026-04-13T15:28:24.152831Z",
                                "id": "CVE-2026-40194",
                                "options": [
                                    {
                                        "Exploitation": "poc"
                                    },
                                    {
                                        "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": "2026-04-13T15:35:24.775Z"
                }
            }
        ]
    }
}