Apache Airflow's EmailOperator and the underlying `airflow.utils.email` helpers established SMTP STARTTLS connections without verifying the remote certificate when the deployment used `[email] smtp_starttls=True` without `[email] smtp_ssl`. An attacker positioned between the worker and the configured SMTP server (network MITM — typical hostile-network attack-surface for environments where the SMTP relay sits outside the worker's trust boundary) could present a self-signed certificate, have the worker complete the STARTTLS handshake silently, and capture the SMTP AUTH credentials and message contents the worker forwarded. This CVE covers the **core apache-airflow side** of the same root cause already covered for the SMTP provider by `CVE-2026-41016` (published 2026-04-27, covering `apache-airflow-providers-smtp`). Users who already applied the SMTP-provider fix from CVE-2026-41016 should additionally upgrade `apache-airflow` to 3.2.2 or later to cover the core-side path through `airflow.utils.email`. Affects deployments configured with `smtp_starttls=True` and `smtp_ssl=False` where the SMTP relay is reachable across a less-trusted network segment than the worker. Users are advised to upgrade to `apache-airflow` 3.2.2 or later.

Open ISES Tickets before 3.44.2 disables TLS certificate verification in rm/incs/mobile_login.inc.php by setting CURLOPT_SSL_VERIFYPEER to false (and not setting CURLOPT_SSL_VERIFYHOST) when issuing outbound HTTPS requests issued during the mobile (RouteMate) login flow. An attacker positioned on the network path between the server and the remote endpoint can present a forged certificate to intercept, monitor, or modify the request and response, including any API keys or session-bearing data in transit.

Open ISES Tickets before 3.44.2 disables TLS certificate verification in incs/functions.inc.php by setting CURLOPT_SSL_VERIFYPEER to false (and not setting CURLOPT_SSL_VERIFYHOST) when issuing outbound HTTPS requests for general-purpose outbound HTTPS requests issued by the shared helper functions. An attacker positioned on the network path between the server and the remote endpoint can present a forged certificate to intercept, monitor, or modify the request and response, including any API keys or session-bearing data in transit.

Open ISES Tickets before 3.44.2 disables TLS certificate verification in ajax/reports.php by setting CURLOPT_SSL_VERIFYPEER to false (and not setting CURLOPT_SSL_VERIFYHOST) when issuing outbound HTTPS requests for Google Maps Directions API lookups during incident report generation. An attacker positioned on the network path between the server and the remote endpoint can present a forged certificate to intercept, monitor, or modify the request and response, including any API keys or session-bearing data in transit.

Open ISES Tickets before 3.44.2 disables TLS certificate verification in incs/login.inc.php by setting CURLOPT_SSL_VERIFYPEER to false (and not setting CURLOPT_SSL_VERIFYHOST) when issuing outbound HTTPS requests issued during the login/authentication flow. An attacker positioned on the network path between the server and the remote endpoint can present a forged certificate to intercept, monitor, or modify the request and response, including any API keys or session-bearing data in transit.

GNOME Geary before 3.36.3 mishandles pinned TLS certificate verification for IMAP and SMTP services using invalid TLS certificates (e.g., self-signed certificates) when the client system is not configured to use a system-provided PKCS#11 store. This allows a meddler in the middle to present a different invalid certificate to intercept incoming and outgoing mail.

Citrix SD-WAN 10.2.x before 10.2.6 and 11.0.x before 11.0.3 has Missing SSL Certificate Validation.

When Security Assertion Markup Language (SAML) authentication is enabled, Juniper Networks Mist Cloud UI might incorrectly process invalid authentication certificates which could allow a malicious network-based user to access unauthorized data. This issue affects all Juniper Networks Mist Cloud UI versions prior to September 2 2020.

A flaw was found in Keycloak in versions before 10.0.0, where it does not perform the TLS hostname verification while sending emails using the SMTP server. This flaw allows an attacker to perform a man-in-the-middle (MITM) attack.

Apache Airflow's SMTP provider `SmtpHook` called Python's `smtplib.SMTP.starttls()` without an SSL context, so no certificate validation was performed on the TLS upgrade. A man-in-the-middle between the Airflow worker and the SMTP server could present a self-signed certificate, complete the STARTTLS upgrade, and capture the SMTP credentials sent during the subsequent `login()` call. Users are advised to upgrade to the `apache-airflow-providers-smtp` version that contains the fix.

The mobiGate App for Android version 2.2.1.2 and earlier and mobiGate App for iOS version 2.2.4.1 and earlier do not verify X.509 certificates from SSL servers, which allows man-in-the-middle attackers to spoof servers and obtain sensitive information via a crafted certificate.

IBM Security Access Manager 9.0.1 through 9.0.6 does not validate, or incorrectly validates, a certificate which could allow an attacker to spoof a trusted entity by using a man-in-the-middle (MITM) attack. IBM X-Force ID: 158510.

Kintone mobile for Android 1.0.0 through 1.0.5 does not verify SSL server certificates.

Photopt for Android before 2.0.1 does not verify SSL certificates.

Shotwell version 0.22.0 (and possibly other versions) is vulnerable to a TLS/SSL certification validation flaw resulting in a potential for man in the middle attacks.

A vulnerability was found in HTC One/Sense 4.x. It has been rated as problematic. Affected by this issue is the certification validation of the mail client. An exploit has been disclosed to the public and may be used.

An issue in S3Browser v.11.4.5 and v.10.9.9 and fixed in v.11.5.7 allows a remote attacker to obtain sensitive information via the S3 compatible storage component.

Traefik 2.x, in certain configurations, allows HTTPS sessions to proceed without mutual TLS verification in a situation where ERR_BAD_SSL_CLIENT_AUTH_CERT should have occurred.

ELinks 0.12 and Twibright Links 2.3 have Missing SSL Certificate Validation.

A vulnerability in Cisco Webex Meetings Mobile (iOS) could allow an unauthenticated, remote attacker to gain unauthorized read access to sensitive data by using an invalid Secure Sockets Layer (SSL) certificate. The vulnerability is due to insufficient SSL certificate validation by the affected software. An attacker could exploit this vulnerability by supplying a crafted SSL certificate to an affected device. A successful exploit could allow the attacker to conduct man-in-the-middle attacks to decrypt confidential information on user connections to the affected software.

A vulnerability in the Web Services Management Agent (WSMA) feature of Cisco Industrial Network Director (IND) could allow an unauthenticated, remote attacker to gain unauthorized read access to sensitive data using an invalid X.509 certificate. The vulnerability is due to insufficient X.509 certificate validation when establishing a WSMA connection. An attacker could exploit this vulnerability by supplying a crafted X.509 certificate during the WSMA connection setup phase. A successful exploit could allow the attacker to conduct man-in-the-middle attacks to decrypt confidential information on WSMA connections to the affected software. At the time of publication, this vulnerability affected Cisco IND Software releases prior to 1.7.

A missing secure communication definition and an incomplete TLS validation in the upgrade service in B&R Automation Studio versions 4.0.x, 4.1.x, 4.2.x, < 4.3.11SP, < 4.4.9SP, < 4.5.5SP, < 4.6.4 and < 4.7.2 enable unauthenticated users to perform MITM attacks via the B&R upgrade server.

A vulnerability in the Cisco Smart Call Home feature of Cisco IOS and IOS XE Software could allow an unauthenticated, remote attacker to gain unauthorized read access to sensitive data using an invalid certificate. The vulnerability is due to insufficient certificate validation by the affected software. An attacker could exploit this vulnerability by supplying a crafted certificate to an affected device. A successful exploit could allow the attacker to conduct man-in-the-middle attacks to decrypt confidential information on user connections to the affected software.

HttpUtils#getURLConnection method disables explicitly hostname verification for HTTPS connections making clients vulnerable to man-in-the-middle attacks. Calcite uses internally this method to connect with Druid and Splunk so information leakage may happen when using the respective Calcite adapters. The method itself is in a utility class so people may use it to create vulnerable HTTPS connections for other applications. From Apache Calcite 1.26 onwards, the hostname verification will be performed using the default JVM truststore.

An issue was discovered in ssl.c in Axel before 2.17.8. The TLS implementation lacks hostname verification.

The Restaurant Karaoke SHIDAX app 1.3.3 and earlier on Android does not verify SSL certificates, which allows remote attackers to obtain sensitive information via a man-in-the-middle attack.

In JetBrains YouTrack before 2024.1.29548 the SMTPS protocol communication lacked proper certificate hostname validation

The libcurl CURLOPT_SSL_VERIFYPEER option was disabled on a subset of requests made by Nest production devices which enabled a potential man-in-the-middle attack on requests to Google cloud services by any host the traffic was routed through.

Missing SSL Certificate Validation in the Nutfind.com application through 3.9.12 for Android allows a man-in-the-middle attacker to sniff and manipulate all API requests, including login credentials and location data.

A vulnerability in the SSL/TLS implementation of Cisco Nexus Dashboard Orchestrator (NDO) could allow an unauthenticated, remote attacker to intercept sensitive information from an affected device.&nbsp; This vulnerability exists because the Cisco NDO Validate Peer Certificate site management feature validates the certificates for Cisco Application Policy Infrastructure Controller (APIC), Cisco Cloud Network Controller (CNC), and Cisco Nexus Dashboard only when a new site is added or an existing one is reregistered. An attacker could exploit this vulnerability by using machine-in-the-middle techniques to intercept the traffic between the affected device and Cisco NDO and then using a crafted certificate to impersonate the affected device. A successful exploit could allow the attacker to learn sensitive information during communications between these devices.

The Subsonic Music Streamer application 4.4 for Android has Improper Certificate Validation of the Subsonic server certificate, which might allow man-in-the-middle attackers to obtain interaction data.

An information disclosure vulnerability exists in the way Rome SDK handles server SSL/TLS certificate validation, aka 'Rome SDK Information Disclosure Vulnerability'.

A vulnerability in certificate validation processing of Cisco Catalyst SD-WAN Manager, formerly Cisco SD-WAN vManage, could allow an unauthenticated, remote attacker to gain access to sensitive information. This vulnerability is due to improper validation of certificates that are used by the Smart Licensing feature. An attacker with a privileged network position could exploit this vulnerability by intercepting traffic that is sent over the Internet. A successful exploit could allow the attacker to gain access to sensitive information, including credentials used by the device to connect to Cisco cloud services.

A man-in-the-middle vulnerability related to vCenter access was found in Cohesity DataPlatform version 5.x and 6.x prior to 6.1.1c. Cohesity clusters did not verify TLS certificates presented by vCenter. This vulnerability could expose Cohesity user credentials configured to access vCenter.

Mod_gnutls is a TLS module for Apache HTTPD based on GnuTLS. Prior to version 0.13.0, code for client certificate verification did not check the key purpose as set in the Extended Key Usage extension. An attacker with access to the private key for a valid certificate issued by a CA trusted for TLS client authentication but designated for a different purpose could have used that certificate to improperly access resources requiring TLS client authentication. Server configurations that do not use client certificates (`GnuTLSClientVerify ignore`, the default) are not affected. The problem has been fixed in version 0.13.0 by rewriting certificate verification to use `gnutls_certificate_verify_peers()`, and requiring key purpose id-kp-clientAuth (also known as `tls_www_client` in GnuTLS) by default if the Extended Key Usage extension is present. The new `GnuTLSClientKeyPurpose` option allows overriding the expected key purpose if needed (please see the manual for details). Behavior for certificates without an Extended Key Usage extension is unchanged. If dedicated (sub-)CAs are used for issuing TLS client certificates only (not for any other purposes) the issue has no practical impact.

Citrix SD-WAN 10.2.x before 10.2.1 and NetScaler SD-WAN 10.0.x before 10.0.7 have Improper Certificate Validation.

Jenkins Koji Plugin disables SSL/TLS and hostname verification globally for the Jenkins master JVM.

Jenkins SiteMonitor Plugin 0.5 and earlier disabled SSL/TLS and hostname verification globally for the Jenkins master JVM.

Jenkins Codefresh Integration Plugin 1.8 and earlier disables SSL/TLS and hostname verification globally for the Jenkins master JVM.

The Neon app 1.6.14 iOS does not verify X.509 certificates from SSL servers, which allows remote attackers to spoof servers and obtain sensitive information via a crafted certificate.

A man-in-the-middle vulnerability related to vCenter access was found in Rubrik CDM 3.x and 4.x before 4.0.4-p2. This vulnerability might expose Rubrik user credentials configured to access vCenter as Rubrik clusters did not verify TLS certificates presented by vCenter.

An exploitable information disclosure vulnerability exists in the crash handler of the hubCore binary of the Samsung SmartThings Hub STH-ETH-250 - Firmware version 0.20.17. When hubCore crashes, Google Breakpad is used to record minidumps, which are sent over an insecure HTTPS connection to the backtrace.io service, leading to the exposure of sensitive data. An attacker can impersonate the remote backtrace.io server in order to trigger this vulnerability.

ANA App for Android 3.1.1 and earlier, and ANA App for iOS 3.3.6 and earlier does not verify SSL certificates.

SAP Business One Android application, version 1.2, does not verify the certificate properly for HTTPS connection. This allows attacker to do MITM attack.

CertificatePinner.java in OkHttp 3.x through 3.12.0 allows man-in-the-middle attackers to bypass certificate pinning by changing SSLContext and the boolean values while hooking the application. NOTE: This id is disputed because some parties don't consider this is a vulnerability. Their rationale can be found in https://github.com/square/okhttp/issues/4967

The DDNS update function in ADM fails to properly validate the hostname of the DDNS server's TLS/SSL certificate. Although the connection uses HTTPS, an improper validated TLS/SSL certificates allows a remote attacker can intercept the communication to perform a Man-in-the-Middle (MitM) attack, which may obtain the sensitive information of DDNS updating process, including the user's account email, MD5 hashed password, and device serial number.This issue affects ADM: from 4.1.0 through 4.3.3.ROF1, from 5.0.0 through 5.1.1.RCI1.

The API communication component fails to validate the SSL/TLS certificate when sending HTTPS requests to the server. An improper certificates validation vulnerability allows an unauthenticated remote attacker can perform a Man-in-the-Middle (MitM) attack to intercept the cleartext communication, potentially leading to the exposure of sensitive user information, including account emails, MD5 hashed passwords, and device serial numbers. Affected products and versions include: from ADM 4.1.0 through ADM 4.3.3.ROF1 as well as from ADM 5.0.0 through ADM 5.1.1.RCI1.

AudioCodes 440HD and 450HD devices 3.1.2.89 and earlier allows man-in-the-middle attackers to obtain sensitive credential information by leveraging failure to validate X.509 certificates when used with an on-premise installation with Skype for Business.

Polycom VVX 500 and 601 devices 5.8.0.12848 and earlier allows man-in-the-middle attackers to obtain sensitive credential information by leveraging failure to validate X.509 certificates when used with an on-premise installation with Skype for Business.

When the user set the Notification's sender to send emails to the SMTP server via msmtp, an improper validated TLS/SSL certificates allows an attacker who can intercept network traffic between the SMTP client and server to execute a man-in-the-middle (MITM) attack, which may obtain the sensitive information of the SMTP. Affected products and versions include: from ADM 4.1.0 through ADM 4.3.3.RKD2 as well as from ADM 5.0.0 through ADM 5.1.0.RN42.