{"id":"JLSEC-2025-212","summary":"An issue was discovered in Mbed TLS before 2.24.0","details":"An issue was discovered in Mbed TLS before 2.24.0. The verification of X.509 certificates when matching the expected common name (the cn argument of `mbedtls_x509_crt_verify`) with the actual certificate name is mishandled: when the subjecAltName extension is present, the expected name is compared to any name in that extension regardless of its type. This means that an attacker could impersonate a 4-byte or 16-byte domain by getting a certificate for the corresponding IPv4 or IPv6 address (this would require the attacker to control that IP address, though).","modified":"2026-07-23T22:30:19.640828485Z","published":"2025-11-21T15:59:04.054Z","upstream":["CVE-2020-36477"],"database_specific":{"license":"CC-BY-4.0","sources":[{"html_url":"https://nvd.nist.gov/vuln/detail/CVE-2020-36477","database_specific":{"status":"Modified"},"id":"CVE-2020-36477","imported":"2026-07-17T20:45:36.836Z","modified":"2026-06-17T03:15:34.560Z","published":"2021-08-23T02:15:07.043Z","url":"https://services.nvd.nist.gov/rest/json/cves/2.0?cveId=CVE-2020-36477"}]},"references":[{"type":"WEB","url":"https://github.com/ARMmbed/mbedtls/issues/3498"},{"type":"WEB","url":"https://github.com/ARMmbed/mbedtls/releases/tag/v2.24.0"},{"type":"WEB","url":"https://security.gentoo.org/glsa/202301-08"}],"affected":[{"package":{"name":"MbedTLS_jll","ecosystem":"Julia","purl":"pkg:julia/MbedTLS_jll?uuid=c8ffd9c3-330d-5841-b78e-0817d7145fa1"},"ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"2.24.0+0"}]}],"database_specific":{"source":"https://github.com/JuliaLang/SecurityAdvisories.jl/tree/generated/osv/2025/JLSEC-2025-212.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V2","score":"AV:N/AC:M/Au:N/C:N/I:P/A:N"},{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N"}]}