{"id":"CVE-2026-46428","revision":"c21ac794562d46f590156a29770d84f6","records":[{"revision":"c21ac794562d46f590156a29770d84f6","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-46428","aliases":[],"title":"lettre has TLS hostname verification disabled when using Boring TLS backend","description":"lettre is a a mailer library for Rust. Starting in version 0.10.1 and prior to version 0.11.22, an inverted-boolean bug in lettre's `boring-tls` integration silently disables TLS hostname verification for callers using the default (strict) configuration. An on-path attacker presenting any chain-valid certificate for any domain can intercept SMTP submission, including PLAIN/LOGIN credentials and message contents, against any lettre user built with the `boring-tls` feature. Other TLS backends (`native-tls`, `rustls`) are unaffected. Version 0.11.22 patches the issue.","state":0,"publishedAt":"2026-07-20T15:37:58.396+00:00","modifiedAt":"2026-07-21T15:49:36.495+00:00","affected":[{"ecosystem":"Vendor product","name":"lettre","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"vendor\": \"lettre\",\n                    \"product\": \"lettre\",\n                    \"versions\": [\n                        {\n                            \"version\": \">= 0.10.1, < 0.11.22\",\n                            \"status\": \"affected\"\n                        }\n                    ]\n                }"}],"metrics":[{"system":"CVSS 4.0","vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:L/SI:L/SA:N","score":9.1,"severity":"CRITICAL"}],"references":["https://github.com/lettre/lettre/security/advisories/GHSA-4pj9-g833-qx53","https://github.com/lettre/lettre/commit/f5efffc88360dbdbfcef80f465e42d5bce68ca35","https://github.com/lettre/lettre/releases/tag/v0.11.22","https://rustsec.org/advisories/RUSTSEC-2026-0141.html"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-46428","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-46428","identifiers":["CVE-2026-46428"]},"retained":false,"historicalAffected":[]}],"coverage":[]}