CVE-2026-41319 MailKit has STARTTLS Response Injection via unflushed stream buffer that enables SASL mechanism downgrade

MailKit is a cross-platform mail client library built on top of MimeKit. A STARTTLS Response Injection vulnerability in versions prior to 4.16.0 allows a Man-in-the-Middle attacker to inject arbitrary protocol responses across the plaintext-to-TLS trust boundary, enabling SASL authentication...

CVE-2026-41319

MailKit is a cross-platform mail client library built on top of MimeKit. A STARTTLS Response Injection vulnerability in versions prior to 4.16.0 allows a Man-in-the-Middle attacker to inject arbitrary protocol responses across the plaintext-to-TLS trust boundary, enabling SASL authentication...

EUVD-2026-25388

MailKit is a cross-platform mail client library built on top of MimeKit. A STARTTLS Response Injection vulnerability in versions prior to 4.16.0 allows a Man-in-the-Middle attacker to inject arbitrary protocol responses across the plaintext-to-TLS trust boundary, enabling SASL authentication...

CVE-2026-41319

Summary (CVE-2026-41319) MailKit (MimeKit-based) exposes a STARTTLS vulnerability where the internal read buffers of SmtpStream, ImapStream, and Pop3Stream are not flushed when upgrading to TLS with SslStream. This allows pre-TLS attacker-injected data to be treated as post-TLS, enabling a MITM-b...

CVE-2026-41319 MailKit has STARTTLS Response Injection via unflushed stream buffer that enables SASL mechanism downgrade

MailKit is a cross-platform mail client library built on top of MimeKit. A STARTTLS Response Injection vulnerability in versions prior to 4.16.0 allows a Man-in-the-Middle attacker to inject arbitrary protocol responses across the plaintext-to-TLS trust boundary, enabling SASL authentication...

CVE-2026-41319 MailKit has STARTTLS Response Injection via unflushed stream buffer that enables SASL mechanism downgrade

MailKit is a cross-platform mail client library built on top of MimeKit. A STARTTLS Response Injection vulnerability in versions prior to 4.16.0 allows a Man-in-the-Middle attacker to inject arbitrary protocol responses across the plaintext-to-TLS trust boundary, enabling SASL authentication...

CVE-2026-40594 pyLoad: Session Cookie Security Downgrade via Untrusted X-Forwarded-Proto Header Spoofing (Global State Race Condition)

pyLoad is a free and open-source download manager written in Python. Prior to 0.5.0b3.dev98, the setsessioncookiesecure beforerequest handler in src/pyload/webui/app/init.py reads the X-Forwarded-Proto header from any HTTP request without validating that the request originates from a trusted prox...

Selection of Less-Secure Algorithm During Negotiation ('Algorithm Downgrade')

Overview aws-encryption-sdk is an AWS Encryption SDK implementation for Python Affected versions of this package are vulnerable to Selection of Less-Secure Algorithm During Negotiation 'Algorithm Downgrade' via the shared key cache. An attacker can bypass key commitment policy enforcement by...

CVE-2026-6550

Cryptographic algorithm downgrade in the caching layer of Amazon AWS Encryption SDK for Python before version 3.3.1 and before version 4.0.5 might allow an authenticated local threat actor to bypass key commitment policy enforcement via a shared key cache, resulting in ciphertext that can be...

​​Supply Chain Compromise Impacts Axios Node Package Manager​

The Cybersecurity and Infrastructure Security Agency CISA is releasing this alert to provide guidance in response to the software supply chain compromise of the Axios node package manager npm.1 Axios is an HTTP client for JavaScript that developers commonly use in Node.js and browser environments...

PT-2026-33829

Name of the Vulnerable Software and Affected Versions Amazon AWS Encryption SDK for Python versions prior to 3.3.1 Amazon AWS Encryption SDK for Python versions prior to 4.0.5 Description A cryptographic algorithm downgrade in the caching layer may allow an authenticated local threat actor to...

DEBIAN-CVE-2026-40490

The AsyncHttpClient AHC library allows Java applications to easily execute HTTP requests and asynchronously process HTTP responses. When redirect following is enabled followRedirecttrue, versions of AsyncHttpClient prior to 3.0.9 and 2.14.5 forward Authorization and Proxy-Authorization headers...

CVE-2026-40490 AsyncHttpClient leaks authorization credentials to untrusted domains on cross-origin redirects

The AsyncHttpClient AHC library allows Java applications to easily execute HTTP requests and asynchronously process HTTP responses. When redirect following is enabled followRedirecttrue, versions of AsyncHttpClient prior to 3.0.9 and 2.14.5 forward Authorization and Proxy-Authorization headers...

CVE-2026-40490

The CVE-2026-40490 vulnerability affects AsyncHttpClient (AHC). In versions prior to 3.0.9 and 2.14.5, when redirect following is enabled, AHC forwards Authorization and Proxy-Authorization headers (and Realm credentials) to redirect targets across domains, enabling credential leakage via cross-o...

GHSA-9J88-VVJ5-VHGR MailKit has STARTTLS Response Injection via unflushed stream buffer that enables SASL mechanism downgrade

Summary A STARTTLS Response Injection vulnerability in MailKit allows a Man-in-the-Middle attacker to inject arbitrary protocol responses across the plaintext-to-TLS trust boundary, enabling SASL authentication mechanism downgrade e.g., forcing PLAIN instead of SCRAM-SHA-256. The internal read...

MailKit has STARTTLS Response Injection via unflushed stream buffer that enables SASL mechanism downgrade

Summary A STARTTLS Response Injection vulnerability in MailKit allows a Man-in-the-Middle attacker to inject arbitrary protocol responses across the plaintext-to-TLS trust boundary, enabling SASL authentication mechanism downgrade e.g., forcing PLAIN instead of SCRAM-SHA-256. The internal read...

PT-2026-34845

Name of the Vulnerable Software and Affected Versions MailKit versions prior to 4.16.0 Description A STARTTLS Response Injection issue allows a Man-in-the-Middle attacker to inject arbitrary protocol responses across the plaintext-to-TLS trust boundary. This can enable a SASL authentication...

Time-of-check Time-of-use (TOCTOU) Race Condition

Overview openclaw is a 🦞 OpenClaw — Personal AI Assistant Affected versions of this package are vulnerable to Time-of-check Time-of-use TOCTOU Race Condition due to missed detection of local async exec completion events during heartbeat owner downgrade. An attacker can maintain a process in a mor...

OpenClaw: Heartbeat owner downgrade missed local async exec completion events

Summary Heartbeat owner downgrade missed local async exec completion events. Affected Packages / Versions - Package: openclaw - Ecosystem: npm - Affected versions: = 2026.3.31 = 2026.4.10 Impact Local background exec completion text could be missed by heartbeat owner-downgrade detection, leaving ...

GHSA-G375-H3V6-4873 OpenClaw: Heartbeat owner downgrade missed local async exec completion events

Summary Heartbeat owner downgrade missed local async exec completion events. Affected Packages / Versions - Package: openclaw - Ecosystem: npm - Affected versions: = 2026.3.31 = 2026.4.10 Impact Local background exec completion text could be missed by heartbeat owner-downgrade detection, leaving ...