{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2026-77696",
        "assignerOrgId": "3a12439a-ef3a-4c79-92e6-6081a721f1e5",
        "state": "PUBLISHED",
        "assignerShortName": "openssl",
        "dateReserved": "2026-08-21T07:47:36.032Z",
        "datePublished": "2026-09-29T15:32:22.520Z",
        "dateUpdated": "2026-09-29T16:51:33.618Z"
    },
    "containers": {
        "cna": {
            "affected": [
                {
                    "defaultStatus": "unaffected",
                    "product": "OpenSSL",
                    "vendor": "OpenSSL",
                    "versions": [
                        {
                            "lessThan": "4.0.3",
                            "status": "affected",
                            "version": "4.0.0",
                            "versionType": "semver"
                        },
                        {
                            "lessThan": "3.6.5",
                            "status": "affected",
                            "version": "3.6.0",
                            "versionType": "semver"
                        },
                        {
                            "lessThan": "3.5.9",
                            "status": "affected",
                            "version": "3.5.0",
                            "versionType": "semver"
                        },
                        {
                            "lessThan": "3.4.8",
                            "status": "affected",
                            "version": "3.4.0",
                            "versionType": "semver"
                        },
                        {
                            "lessThan": "3.0.23",
                            "status": "affected",
                            "version": "3.0.0",
                            "versionType": "semver"
                        },
                        {
                            "lessThan": "1.1.1zj",
                            "status": "affected",
                            "version": "1.1.1",
                            "versionType": "custom"
                        }
                    ]
                }
            ],
            "credits": [
                {
                    "lang": "en",
                    "type": "reporter",
                    "value": "Vladimir Tokarev"
                },
                {
                    "lang": "en",
                    "type": "remediation developer",
                    "value": "Igor Ustinov"
                },
                {
                    "lang": "en",
                    "type": "remediation developer",
                    "value": "Viktor Dukhovni"
                }
            ],
            "datePublic": "2026-09-29T14:21:57.000Z",
            "descriptions": [
                {
                    "lang": "en",
                    "supportingMedia": [
                        {
                            "base64": false,
                            "type": "text/html",
                            "value": "Issue summary: SM2 signature generation uses non-constant-time arithmetic<br>on secret values, forming a timing side-channel.<br><br>Impact summary: An attacker able to measure SM2 signing times may learn<br>information about the per-signature secret nonce, which over many signatures<br>can, via a lattice / Hidden Number Problem attack, lead to recovery of the<br>private key.<br><br>CWE: CWE-208: Observable Timing Discrepancy<br><br>Description: SM2 signature generation computes the signature value using<br>variable-time BIGNUM operations on the secret nonce and the private key, so<br>the time taken to produce an SM2 signature depends on these secret values,<br>forming a timing side-channel.<br><br>Applications performing SM2 signature generation are affected on all<br>platforms.<br><br>FIPS Impact: no<br>SM2 is not a FIPS algorithm."
                        }
                    ],
                    "value": "Issue summary: SM2 signature generation uses non-constant-time arithmetic\non secret values, forming a timing side-channel.\n\nImpact summary: An attacker able to measure SM2 signing times may learn\ninformation about the per-signature secret nonce, which over many signatures\ncan, via a lattice / Hidden Number Problem attack, lead to recovery of the\nprivate key.\n\nCWE: CWE-208: Observable Timing Discrepancy\n\nDescription: SM2 signature generation computes the signature value using\nvariable-time BIGNUM operations on the secret nonce and the private key, so\nthe time taken to produce an SM2 signature depends on these secret values,\nforming a timing side-channel.\n\nApplications performing SM2 signature generation are affected on all\nplatforms.\n\nFIPS Impact: no\nSM2 is not a FIPS algorithm."
                }
            ],
            "metrics": [
                {
                    "format": "other",
                    "other": {
                        "content": {
                            "text": "Low"
                        },
                        "type": "https://openssl-library.org/policies/general/security-policy/"
                    }
                }
            ],
            "problemTypes": [
                {
                    "descriptions": [
                        {
                            "cweId": "CWE-208",
                            "description": "CWE-208 Observable Timing Discrepancy",
                            "lang": "en",
                            "type": "CWE"
                        }
                    ]
                }
            ],
            "providerMetadata": {
                "orgId": "3a12439a-ef3a-4c79-92e6-6081a721f1e5",
                "shortName": "openssl",
                "dateUpdated": "2026-09-29T15:32:22.520Z"
            },
            "references": [
                {
                    "name": "OpenSSL Advisory",
                    "tags": [
                        "vendor-advisory"
                    ],
                    "url": "https://openssl-library.org/news/secadv/20260929.txt"
                },
                {
                    "name": "4.0.3 git commit",
                    "tags": [
                        "patch"
                    ],
                    "url": "https://github.com/openssl/openssl/commit/20b20628d39b2dcc4677194bd68c7c060fa598cb"
                },
                {
                    "name": "3.6.5 git commit",
                    "tags": [
                        "patch"
                    ],
                    "url": "https://github.com/openssl/openssl/commit/1c4aed808a7aea32d2d013049c2e0d9fef164fc9"
                },
                {
                    "name": "3.5.9 git commit",
                    "tags": [
                        "patch"
                    ],
                    "url": "https://github.com/openssl/openssl/commit/6b90445a56b99a328ac1feba058abf976504f440"
                },
                {
                    "name": "3.4.8 git commit",
                    "tags": [
                        "patch"
                    ],
                    "url": "https://github.com/openssl/openssl/commit/419f5cb519721dceed393dbc524d79e487c72e64"
                }
            ],
            "source": {
                "discovery": "UNKNOWN"
            },
            "title": "Timing Side-Channel in SM2 Signature Generation",
            "x_generator": {
                "engine": "Vulnogram 0.2.0"
            }
        },
        "adp": [
            {
                "metrics": [
                    {
                        "cvssV3_1": {
                            "scope": "UNCHANGED",
                            "version": "3.1",
                            "baseScore": 3.7,
                            "attackVector": "NETWORK",
                            "baseSeverity": "LOW",
                            "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N",
                            "integrityImpact": "NONE",
                            "userInteraction": "NONE",
                            "attackComplexity": "HIGH",
                            "availabilityImpact": "NONE",
                            "privilegesRequired": "NONE",
                            "confidentialityImpact": "LOW"
                        }
                    },
                    {
                        "other": {
                            "type": "ssvc",
                            "content": {
                                "timestamp": "2026-09-29T16:51:30.070097Z",
                                "id": "CVE-2026-77696",
                                "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": "2026-09-29T16:51:33.618Z"
                }
            }
        ]
    }
}