{"id":"JLSEC-2026-1377","details":"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.","modified":"2026-08-24T14:00:03.437583556Z","published":"2026-08-24T13:43:17.899Z","upstream":["CVE-2026-73253","EUVD-2026-63500"],"database_specific":{"license":"CC-BY-4.0","sources":[{"imported":"2026-08-23T06:20:12.239Z","modified":"2026-08-20T19:17:01.203Z","published":"2026-08-20T18:16:45.940Z","url":"https://services.nvd.nist.gov/rest/json/cves/2.0?cveId=CVE-2026-73253","html_url":"https://nvd.nist.gov/vuln/detail/CVE-2026-73253","database_specific":{"status":"Received"},"id":"CVE-2026-73253"},{"affected":{"Cesanta:Mongoose":["\u003c 7.22"]},"id":"EUVD-2026-63500","imported":"2026-08-23T06:20:06.545Z","modified":"2026-08-20T18:36:17Z","published":"2026-08-20T17:41:02Z","url":"https://euvdservices.enisa.europa.eu/api/enisaid?id=EUVD-2026-63500","html_url":"https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-63500"}]},"references":[{"type":"WEB","url":"https://github.com/cesanta/mongoose/commit/a9df523f76f43a38bd53b4232b9cfd4c16869e71"},{"type":"WEB","url":"https://github.com/cesanta/mongoose/pull/3611"},{"type":"WEB","url":"https://github.com/cesanta/mongoose/releases/tag/7.22"},{"type":"WEB","url":"https://github.com/cesanta/mongoose/security/advisories/GHSA-jp6g-796f-39vp"}],"affected":[{"package":{"name":"Mongoose_jll","ecosystem":"Julia","purl":"pkg:julia/Mongoose_jll?uuid=0a8a3f5b-4c0e-5906-8e29-5b3fee15539c"},"ranges":[{"type":"SEMVER","events":[{"introduced":"0"}]}],"database_specific":{"source":"https://github.com/JuliaLang/SecurityAdvisories.jl/tree/generated/osv/2026/JLSEC-2026-1377.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V4","score":"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","source":"CNA"}]}