{"id":"EUVD-2026-45982","enisaUuid":"bacd74ea-c014-3831-a611-a0f0cb3253da","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\u0027s `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.","datePublished":"Jul 20, 2026, 3:37:58 PM","dateUpdated":"Jul 21, 2026, 3:49:36 PM","baseScore":9.1,"baseScoreVersion":"4.0","baseScoreVector":"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","references":"https://github.com/lettre/lettre/security/advisories/GHSA-4pj9-g833-qx53\nhttps://github.com/lettre/lettre/commit/f5efffc88360dbdbfcef80f465e42d5bce68ca35\nhttps://github.com/lettre/lettre/releases/tag/v0.11.22\nhttps://rustsec.org/advisories/RUSTSEC-2026-0141.html\n","aliases":"CVE-2026-46428\nGHSA-4pj9-g833-qx53\n","assigner":"GitHub_M","epss":0.32,"enisaIdProduct":[{"id":"5311e49b-5df3-3758-9f95-af0f0202e554","product":{"name":"lettre","vendor":{"name":"lettre"}},"product_version":"0.10.1, \u003c 0.11.22"}],"enisaIdVendor":[{"id":"2683be06-d32d-31c8-b6ae-34556c469ae3","vendor":{"name":"lettre"}}],"enisaIdVulnerability":[{"id":"12c30e84-a60d-3a37-a2c4-38a03464e288","vulnerability":{"id":"CVE-2026-46428","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\u0027s `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.","datePublished":"Jul 20, 2026, 3:37:58 PM","dateUpdated":"Jul 21, 2026, 3:49:36 PM","status":"PUBLISHED","baseScore":9.1,"baseScoreVersion":"4.0","baseScoreVector":"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","references":"https://github.com/lettre/lettre/security/advisories/GHSA-4pj9-g833-qx53\nhttps://github.com/lettre/lettre/commit/f5efffc88360dbdbfcef80f465e42d5bce68ca35\nhttps://github.com/lettre/lettre/releases/tag/v0.11.22\nhttps://rustsec.org/advisories/RUSTSEC-2026-0141.html\n","enisa_id":"EUVD-2026-45982\n","assigner":"GitHub_M","epss":0.32,"dataProcessed":"Nov 5, 2026, 7:18:42 AM","vulnerabilityProduct":[{"id":"ee473f3e-51f7-348f-8865-bc04b4c50766","product":{"name":"lettre","vendor":{"name":"lettre"}},"product_version":"0.10.1, \u003c 0.11.22"}],"vulnerabilityVendor":[{"id":"279b4c44-ab10-3915-ba46-85aa3591c3b6","vendor":{"name":"lettre"}}]}},{"id":"4b51bacd-c7ee-3177-9b2c-ef1ef8314edd","vulnerability":{"id":"GHSA-4pj9-g833-qx53","description":"lettre has TLS hostname verification disabled when using Boring TLS backend","datePublished":"Jul 28, 2026, 2:29:10 PM","dateUpdated":"Jul 28, 2026, 2:29:10 PM","baseScore":0.0,"references":"https://github.com/lettre/lettre/security/advisories/GHSA-4pj9-g833-qx53\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-46428\nhttps://github.com/lettre/lettre/commit/f5efffc88360dbdbfcef80f465e42d5bce68ca35\nhttps://github.com/lettre/lettre\nhttps://github.com/lettre/lettre/releases/tag/v0.11.22\nhttps://rustsec.org/advisories/RUSTSEC-2026-0141.html\n","enisa_id":"EUVD-2026-45982\n","aliases":"CVE-2026-46428\nGHSA-4pj9-g833-qx53\n","epss":0.0,"dataProcessed":"Nov 1, 2026, 2:03:08 AM","vulnerabilityProduct":[],"vulnerabilityVendor":[]}}],"enisaIdAdvisory":[]}