{"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"}}]}}

{}

{"affected": [{"affectedData": [{"product": "mongoose", "vendor": "cesanta", "versions": [{"status": "affected", "version": "< 7.22"}]}], "source": "security-advisories@github.com"}], "cveTags": [], "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."}], "id": "CVE-2026-73253", "lastModified": "2026-08-20T19:17:01.203", "metrics": {"cvssMetricV40": [{"cvssData": {"Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "Safety": "NOT_DEFINED", "attackComplexity": "LOW", "attackRequirements": "PRESENT", "attackVector": "NETWORK", "availabilityRequirement": "NOT_DEFINED", "baseScore": 9.1, "baseSeverity": "CRITICAL", "confidentialityRequirement": "NOT_DEFINED", "exploitMaturity": "NOT_DEFINED", "integrityRequirement": "NOT_DEFINED", "modifiedAttackComplexity": "NOT_DEFINED", "modifiedAttackRequirements": "NOT_DEFINED", "modifiedAttackVector": "NOT_DEFINED", "modifiedPrivilegesRequired": "NOT_DEFINED", "modifiedSubAvailabilityImpact": "NOT_DEFINED", "modifiedSubConfidentialityImpact": "NOT_DEFINED", "modifiedSubIntegrityImpact": "NOT_DEFINED", "modifiedUserInteraction": "NOT_DEFINED", "modifiedVulnAvailabilityImpact": "NOT_DEFINED", "modifiedVulnConfidentialityImpact": "NOT_DEFINED", "modifiedVulnIntegrityImpact": "NOT_DEFINED", "privilegesRequired": "NONE", "providerUrgency": "NOT_DEFINED", "subAvailabilityImpact": "NONE", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "userInteraction": "NONE", "valueDensity": "NOT_DEFINED", "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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X", "version": "4.0", "vulnAvailabilityImpact": "NONE", "vulnConfidentialityImpact": "HIGH", "vulnIntegrityImpact": "HIGH", "vulnerabilityResponseEffort": "NOT_DEFINED"}, "source": "security-advisories@github.com", "type": "Secondary"}], "ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-73253", "options": [{"exploitation": "poc"}, {"automatable": "no"}, {"technicalImpact": "total"}], "role": "CISA Coordinator", "timestamp": "2026-08-20T18:33:38.834878Z", "version": "2.0.3"}}]}, "published": "2026-08-20T18:16:45.940", "references": [{"source": "security-advisories@github.com", "url": "https://github.com/cesanta/mongoose/commit/a9df523f76f43a38bd53b4232b9cfd4c16869e71"}, {"source": "security-advisories@github.com", "url": "https://github.com/cesanta/mongoose/pull/3611"}, {"source": "security-advisories@github.com", "url": "https://github.com/cesanta/mongoose/releases/tag/7.22"}, {"source": "security-advisories@github.com", "url": "https://github.com/cesanta/mongoose/security/advisories/GHSA-jp6g-796f-39vp"}, {"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "url": "https://github.com/cesanta/mongoose/security/advisories/GHSA-jp6g-796f-39vp"}], "sourceIdentifier": "security-advisories@github.com", "vulnStatus": "Received", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-295"}], "source": "security-advisories@github.com", "type": "Secondary"}]}

{}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "generic", "value": "[0,7.22)"}}], "enrichment": {"confidence": 100.0, "confidence_source": "matching", "scores": [{"score": 100.0, "source": "matching"}]}, "original": {"product": "mongoose", "source": "cna", "vendor": "cesanta"}, "product": "mongoose", "vendor": "cesanta"}], "created": "2026-08-20T18:30:03.740183+00:00", "updated": "2026-08-20T19:45:03.894336+00:00", "vendors": ["cesanta", "cesanta$PRODUCT$mongoose"]}