CVE-2026-53622 Traefik: HTTP/3 mTLS bypass via exact SNI TLSOptions lookup for wildcard and mixed-case hosts

Traefik is an HTTP reverse proxy and load balancer. Prior to 3.7.3, there is a critical vulnerability in Traefik's HTTP/3 QUIC TLS configuration selection that allows unauthenticated clients to bypass router-specific mTLS enforcement. When HTTP/3 is enabled on an entrypoint, the TLS handshake...

PYSEC-2026-237

AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to 3.14.1, the serverhostname TLS SNI check can be bypassed when an existing connection is reused. If an application makes multiple requests to the same domain, but with different per-request serverhostname...

PYSEC-2026-237

AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to 3.14.1, the serverhostname TLS SNI check can be bypassed when an existing connection is reused. If an application makes multiple requests to the same domain, but with different per-request serverhostname...

CVE-2026-54275

AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to 3.14.1, the serverhostname TLS SNI check can be bypassed when an existing connection is reused. If an application makes multiple requests to the same domain, but with different per-request serverhostname...

EUVD-2026-38312

AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to 3.14.1, the serverhostname TLS SNI check can be bypassed when an existing connection is reused. If an application makes multiple requests to the same domain, but with different per-request serverhostname...

CVE-2026-54275 AIOHTTP: TLS Server Hostname Override Is Ignored When Reusing HTTPS Connections

AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to 3.14.1, the serverhostname TLS SNI check can be bypassed when an existing connection is reused. If an application makes multiple requests to the same domain, but with different per-request serverhostname...

CVE-2026-54275

AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to 3.14.1, the serverhostname TLS SNI check can be bypassed when an existing connection is reused. If an application makes multiple requests to the same domain, but with different per-request serverhostname...

CVE-2026-54275 AIOHTTP: TLS Server Hostname Override Is Ignored When Reusing HTTPS Connections

AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to 3.14.1, the serverhostname TLS SNI check can be bypassed when an existing connection is reused. If an application makes multiple requests to the same domain, but with different per-request serverhostname...

eclipse-vertx/vert.x: eclipse-vertx/vert.x: Denial of Service via TLS handshake with wildcard server name

A flaw was found in eclipse-vertx/vert.x. A remote attacker can exploit this vulnerability by performing a Transport Layer Security TLS handshake and presenting a server name extension with a server wildcard name. This can lead to a denial of service DoS condition, impacting the availability of t...

eclipse-vertx/vert.x: eclipse-vertx/vert.x: Denial of Service via TLS handshake with wildcard server name

A flaw was found in eclipse-vertx/vert.x. A remote attacker can exploit this vulnerability by performing a Transport Layer Security TLS handshake and presenting a server name extension with a server wildcard name. This can lead to a denial of service DoS condition, impacting the availability of t...

GHSA-9CR8-Q42Q-G8M7 Traefik: HTTP/3 mTLS bypass via exact SNI TLSOptions lookup for wildcard and mixed-case hosts

Summary There is a critical vulnerability in Traefik's HTTP/3 QUIC TLS configuration selection that allows unauthenticated clients to bypass router-specific mTLS enforcement. When HTTP/3 is enabled on an entrypoint, the TLS handshake selects the applicable TLS configuration through an exact,...

Authentication Bypass Using an Alternate Path or Channel

Overview github.com/traefik/traefik/v2/pkg/server is a server package for traefik, a cloud native edge router. Affected versions of this package are vulnerable to Authentication Bypass Using an Alternate Path or Channel in the SNICheck process. An attacker can gain unauthorized access to protecte...

Authentication Bypass Using an Alternate Path or Channel

Overview Affected versions of this package are vulnerable to Authentication Bypass Using an Alternate Path or Channel in the SNICheck process. An attacker can gain unauthorized access to protected backends by completing a TLS handshake using a permissive SNI and then sending an HTTP Host header...

Authentication Bypass Using an Alternate Path or Channel

Overview Affected versions of this package are vulnerable to Authentication Bypass Using an Alternate Path or Channel in the SNICheck process. An attacker can gain unauthorized access to protected backends by completing a TLS handshake using a permissive SNI and then sending an HTTP Host header...

Authentication Bypass Using an Alternate Path or Channel

Overview Affected versions of this package are vulnerable to Authentication Bypass Using an Alternate Path or Channel in the SNICheck process. An attacker can gain unauthorized access to protected backends by completing a TLS handshake using a permissive SNI and then sending an HTTP Host header...

PT-2026-50163

Name of the Vulnerable Software and Affected Versions Traefik versions 3.6.17 through 3.7.1 Description An issue in the HTTP/3 QUIC TLS configuration selection allows unauthenticated clients to bypass router-specific mutual TLS mTLS enforcement. When HTTP/3 is enabled, the TLS handshake uses an...

aiohttp: TLS Server Hostname Override Is Ignored When Reusing HTTPS Connections

Summary The serverhostname TLS SNI check can be bypassed when an existing connection is reused. Impact If an application makes multiple requests to the same domain, but with different per-request serverhostname parameters, then the later calls may succeed by reusing the existing connection when...

FreeBSD : h2o -- heap overrun parsing zero-length SNI (fba766f4-ccda-4e1b-8875-ab857c6a6532)

The version of FreeBSD installed on the remote host is prior to tested version. It is, therefore, affected by a vulnerability as referenced in the fba766f4-ccda-4e1b-8875-ab857c6a6532 advisory. h2o project reports: When h2o receives a TLS or QUIC ClientHello containing a zero-length SNI extension...

EulerOS 2.0 SP13 : pyOpenSSL (EulerOS-SA-2026-2351)

According to the versions of the pyOpenSSL packages installed, the EulerOS installation on the remote host is affected by the following vulnerabilities : pyOpenSSL is a Python wrapper around the OpenSSL library. Starting in version 0.14.0 and prior to version 26.0.0, if a user provided callback t...

CVE-2026-5503

In TLSXEchChangeSNI, the ctx-extensions branch set extensions unconditionally even when TLSXFind returned NULL. This caused TLSXUseSNI to attach the attacker-controlled publicName to the shared WOLFSSLCTX when no inner SNI was configured. TLSXEchRestoreSNI then failed to clean it up because its...