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CVE-2026-46428

· Published 20/07/2026 18:17 · Author: The MITRE Corporation

Labels: CVE-2026-46428

Essential information

Published
20/07/2026 18:17
Modified
Author
The MITRE Corporation
Creator
The MITRE Corporation
CVSS
9.1 CRITICAL (v4.0)
CISA KEV
No
CWE
CWE-295
CVSS vector

CVSS metrics

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.

NVD status

NVD
View on NVD