{"schema":"threatline.record/2","record":{"id":"CVE-2026-73260","aliases":["GHSA-f6wr-mg35-p25g"],"summary":"Mongoose: Out-of-bounds Read via length-counter underflow in built-in TLS X.509 DER parser","details":"Mongoose is an embedded web server and network library. Prior to 7.23, the built-in TLS certificate parser selected by MG_TLS_BUILTIN fails to verify that a long-form DER element length fits within the remaining certificate buffer. In mg_der_to_tlv() and mg_der_next(), a peer-controlled length can advance the parser beyond the certificate and underflow the remaining uint32_t length, causing mg_tls_parse_cert_der() to continue walking an invalid pointer. An unauthenticated malicious TLS server, or a client presenting a certificate to a server configured for client certificates, can trigger an out-of-bounds read and denial of service during the handshake. This issue is fixed in version 7.23.","categories":["Unclassified"],"product":"mongoose","vendor":"cesanta","ecosystem":null,"affected_ranges":[{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-73260","source_modified_at":"2026-10-20T01:50:00.898Z","fetched_at":"2026-10-23T18:45:31.882637Z","product":"mongoose","vendor":"cesanta","versions":[{"version":"< 7.23","status":"affected"}],"defaultStatus":null}],"fixed_versions":[],"cvss":7.5,"severity":"High","kev":{"listed":false},"epss":{"probability":0.0023,"percentile":0.1307,"score_date":"2026-10-23"},"published_at":"2026-10-14T18:25:00.518Z","modified_at":"2026-10-20T01:50:00.898Z","provenance":[{"source":"CVE List","url":"https://www.cve.org/CVERecord?id=CVE-2026-73260","fetched_at":"2026-10-23T18:45:31.882637Z","source_modified_at":"2026-10-20T01:50:00.898Z"},{"source":"EPSS","url":"https://api.first.org/data/v1/epss?cve=CVE-2026-73260","fetched_at":"2026-10-23T18:42:43.628194Z","source_modified_at":"2026-10-23"}],"sources":["CVE List","EPSS"],"references":[{"source":"CVE List","url":"https://github.com/cesanta/mongoose/security/advisories/GHSA-f6wr-mg35-p25g","tags":["x_refsource_CONFIRM"]},{"source":"CVE List","url":"https://github.com/cesanta/mongoose/commit/a8b4ae95db3c2db85e5ad9db3fefaeebb5f7b43e","tags":["x_refsource_MISC"]},{"source":"CVE List","url":"https://github.com/cesanta/mongoose/releases/tag/7.23","tags":["x_refsource_MISC"]}],"locations":[],"motoko_assessment":{"status":"requires_architecture_review","automatic_remediation":false},"cve_state":"PUBLISHED","cvss_source":"CVE List","ssvc":{"exploitation":"poc","automatable":"yes","technical_impact":"partial","assessed_at":"2026-10-20T01:49:51.017897Z"},"classification":{"method":"product-first software-layer rules","rules_version":"2.1","matched_on":null,"confidence":"unknown","reviewed":false},"change_timestamp":"2026-10-20T01:50:00.898Z","content_hash":"05674647e444593fc08e04dbbf2c5442f1baacabda035909239ca04b64d8f4eb"}}