CVE-2026-46428

CriticalCVSS 9.1/10Last modified Jul 23, 2026

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.

Metrics

CVSS 4.0 9.1/10

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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Weakness enumeration

CWE-295

Affected software

No affected versions have been published.

Timeline

Published: Jul 20, 2026
Last modified: Jul 23, 2026
NVD status: Deferred

Related CVEs from 2026

CVE-2026-46433.5Mattermost Desktop App versions <=6.1 6.0.1 5.4.13.0 fail to prevent server-rendered content from closing an underlying application view in CVE-2026-464304.3Algernon is a small self-contained pure-Go web server. Prior to 1.17.7, the SSE event server bound to 0.0.0.0:5553 on Linux/macOS by default CVE-2026-464314.3Algernon is a small self-contained pure-Go web server. Prior to 1.17.7, the SSE event server's Access-Control-Allow-Origin response header w CVE-2026-464327.8LMDeploy is a toolkit for compressing, deploying, and serving large language models. In versions 0.12.3 and prior, LMDeploy is vulnerable to CVE-2026-464336.5lldpd is an implementation of IEEE 802.1ab (LLDP). Prior to version 1.0.22, lldpd_decode() in src/daemon/lldpd.c strips 802.1Q VLAN tags fro CVE-2026-464347.1wger is a free, open-source workout and fitness manager. Prior to version 2.6, a user with only the `gym_trainer` permission can deactivate CVE-2026-464374.8wger is a free, open-source workout and fitness manager. Versions prior to 2.6 have a vulnerability in the authentication/session lifecycle CVE-2026-464386.5wger is a free, open-source workout and fitness manager. Prior to version 2.6, an authenticated attacker can inject arbitrary workout log en CVE-2026-464397.8compliance-trestle is a tooling platform for managing compliance as code. Versions prior to 3.12.2 and 4.0.3 have a Server-Side Template Inj CVE-2026-46448.5A Missing Authorization vulnerability in HTTP Connector in Google Cloud Integration Connectors versions prior to 2025-12-11 on Google Cloud CVE-2026-464409.1Flowise is a drag & drop user interface to build a customized large language model flow. Prior to version 3.1.2, the checkBasicAuth endpoint CVE-2026-464419.6Flowise is a drag & drop user interface to build a customized large language model flow. Prior to version 3.1.2, a mass assignment vulnerabi