{"id":"CVE-2018-21246","aliases":["GHSA-gr7w-x2jp-3xgw","GO-2020-0043"],"url":"https://o3.security/vulnerability/CVE-2018-21246","summary":"Caddy vulnerable to Authentication Bypass due to mishandling of TLS client authentication","details":"Caddy before 0.10.13 mishandles TLS client authentication, as demonstrated by an authentication bypass caused by the lack of the StrictHostMatching mode.","published":"2020-06-15T17:15:09.620Z","modified":"2026-07-08T19:45:31.272874Z","cvss":{"score":9.8,"severity":"CRITICAL","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"},"epss":{"score":0.02723,"percentile":0.84867,"asOf":"2026-08-23"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"Go","name":"github.com/caddyserver/caddy","fixedVersion":"0.10.13"}],"fix":{"url":"https://github.com/caddyserver/caddy/pull/2099","label":"caddyserver/caddy#2099"},"references":[{"type":"ADVISORY","url":"https://bugs.gentoo.org/715214"},{"type":"ADVISORY","url":"https://github.com/caddyserver/caddy/releases/tag/v0.10.13"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2018-21246"},{"type":"WEB","url":"https://github.com/caddyserver/caddy/pull/2099"},{"type":"WEB","url":"https://github.com/caddyserver/caddy/commit/4d9ee000c8d2cbcdd8284007c1e0f2da7bc3c7c3"},{"type":"PACKAGE","url":"https://github.com/caddyserver/caddy"},{"type":"WEB","url":"https://pkg.go.dev/vuln/GO-2020-0043"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-07-08T19:45:31.272874Z"}}