{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2026-73253",
        "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "state": "PUBLISHED",
        "assignerShortName": "GitHub_M",
        "dateReserved": "2026-08-11T17:18:01.598Z",
        "datePublished": "2026-08-20T17:41:02.495Z",
        "dateUpdated": "2026-08-20T18:36:17.262Z"
    },
    "containers": {
        "cna": {
            "title": "Mongoose: TLS Hostname Verification Bypass via Overly Permissive Wildcard Matching",
            "problemTypes": [
                {
                    "descriptions": [
                        {
                            "cweId": "CWE-295",
                            "lang": "en",
                            "description": "CWE-295: Improper Certificate Validation",
                            "type": "CWE"
                        }
                    ]
                }
            ],
            "metrics": [
                {
                    "cvssV4_0": {
                        "attackVector": "NETWORK",
                        "attackComplexity": "LOW",
                        "attackRequirements": "PRESENT",
                        "privilegesRequired": "NONE",
                        "userInteraction": "NONE",
                        "vulnConfidentialityImpact": "HIGH",
                        "vulnIntegrityImpact": "HIGH",
                        "vulnAvailabilityImpact": "NONE",
                        "subConfidentialityImpact": "NONE",
                        "subIntegrityImpact": "NONE",
                        "subAvailabilityImpact": "NONE",
                        "baseScore": 9.1,
                        "baseSeverity": "CRITICAL",
                        "vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N",
                        "version": "4.0"
                    }
                }
            ],
            "references": [
                {
                    "name": "https://github.com/cesanta/mongoose/security/advisories/GHSA-jp6g-796f-39vp",
                    "tags": [
                        "x_refsource_CONFIRM"
                    ],
                    "url": "https://github.com/cesanta/mongoose/security/advisories/GHSA-jp6g-796f-39vp"
                },
                {
                    "name": "https://github.com/cesanta/mongoose/pull/3611",
                    "tags": [
                        "x_refsource_MISC"
                    ],
                    "url": "https://github.com/cesanta/mongoose/pull/3611"
                },
                {
                    "name": "https://github.com/cesanta/mongoose/commit/a9df523f76f43a38bd53b4232b9cfd4c16869e71",
                    "tags": [
                        "x_refsource_MISC"
                    ],
                    "url": "https://github.com/cesanta/mongoose/commit/a9df523f76f43a38bd53b4232b9cfd4c16869e71"
                },
                {
                    "name": "https://github.com/cesanta/mongoose/releases/tag/7.22",
                    "tags": [
                        "x_refsource_MISC"
                    ],
                    "url": "https://github.com/cesanta/mongoose/releases/tag/7.22"
                }
            ],
            "affected": [
                {
                    "vendor": "cesanta",
                    "product": "mongoose",
                    "versions": [
                        {
                            "version": "< 7.22",
                            "status": "affected"
                        }
                    ]
                }
            ],
            "providerMetadata": {
                "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
                "shortName": "GitHub_M",
                "dateUpdated": "2026-08-20T17:41:02.495Z"
            },
            "descriptions": [
                {
                    "lang": "en",
                    "value": "Mongoose is an embedded web server and network library. Prior to version 7.22, an on-path network attacker with a wildcard certificate for a parent domain can impersonate deeper subdomains to a client using the built-in TLS stack. The mg_tls_verify_cert_san() and mg_tls_verify_cert_cn() functions in src/tls_builtin.c call mg_match(), whose wildcard can cross DNS label boundaries, so a pattern such as *.example.com can match foo.bar.example.com. The resulting hostname verification bypass permits interception and modification of TLS traffic. This issue is fixed in version 7.22."
                }
            ],
            "source": {
                "advisory": "GHSA-jp6g-796f-39vp",
                "discovery": "UNKNOWN"
            }
        },
        "adp": [
            {
                "references": [
                    {
                        "url": "https://github.com/cesanta/mongoose/security/advisories/GHSA-jp6g-796f-39vp",
                        "tags": [
                            "exploit"
                        ]
                    }
                ],
                "metrics": [
                    {
                        "other": {
                            "type": "ssvc",
                            "content": {
                                "timestamp": "2026-08-20T18:33:38.834878Z",
                                "id": "CVE-2026-73253",
                                "options": [
                                    {
                                        "Exploitation": "poc"
                                    },
                                    {
                                        "Automatable": "no"
                                    },
                                    {
                                        "Technical Impact": "total"
                                    }
                                ],
                                "role": "CISA Coordinator",
                                "version": "2.0.3"
                            }
                        }
                    }
                ],
                "title": "CISA ADP Vulnrichment",
                "providerMetadata": {
                    "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
                    "shortName": "CISA-ADP",
                    "dateUpdated": "2026-08-20T18:36:17.262Z"
                }
            }
        ]
    }
}