libcurl: libcurl: Security feature bypass due to improper mTLS connection reuse

A flaw was found in curl. The libcurl library, used for transferring data with URLs, could improperly reuse existing network connections. This occurred even when changes to mutual Transport Layer Security mTLS settings, particularly those for client certificates, should have prevented such reuse...

CURL-CVE-2026-11564 Native CA trust persist

libcurl keeps previously used connections in a connection pool for subsequent transfers to reuse if one of them matches the setup. An easy handle that first uses default native CA trust can continue trusting the native platform store after the application switches that same handle to custom CA...

CURL-CVE-2026-8286 wrong STARTTLS connection reuse

A vulnerability exists where a new transfer that uses STARTTLS to upgrade the connection might reuse an existing live connection even though the TLS configuration mismatches so it should not...

wrong STARTTLS connection reuse

A vulnerability exists where a new transfer that uses STARTTLS to upgrade the connection might reuse an existing live connection even though the TLS configuration mismatches so it should not...

CURL-CVE-2026-8458 wrong reuse for different services

libcurl might in some circumstances reuse the wrong connection when asked to do Negotiate-authenticated ones, even when they are set to use different "services". libcurl features a pool of recent connections so that subsequent requests can reuse an existing connection to avoid overhead. When...

incomplete mTLS config matching in conn reuse

libcurl would reuse a previously created connection even when some mTLS config related option had been changed that should have prohibited reuse. libcurl keeps previously used connections in a connection pool for subsequent transfers to reuse if one of them matches the setup. However, some TLS...

wrong reuse for different services

libcurl might in some circumstances reuse the wrong connection when asked to do Negotiate-authenticated ones, even when they are set to use different "services". libcurl features a pool of recent connections so that subsequent requests can reuse an existing connection to avoid overhead. When...

CURL-CVE-2026-8932 incomplete mTLS config matching in conn reuse

libcurl would reuse a previously created connection even when some mTLS config related option had been changed that should have prohibited reuse. libcurl keeps previously used connections in a connection pool for subsequent transfers to reuse if one of them matches the setup. However, some TLS...

PT-2026-51751

Name of the Vulnerable Software and Affected Versions libcurl versions 7.7 through 8.20.x Description libcurl incorrectly reuses previously created connections from its connection pool even when mutual TLS mTLS configuration options have changed. The connection-reuse check fails to validate five...

PT-2026-51746

Name of the Vulnerable Software and Affected Versions libcurl affected versions not specified Description A logical error in the connection pooling mechanism allows the software to reuse an incorrect connection for Negotiate-authenticated requests. This occurs even when the requests are configure...

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 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...

CVE-2026-54275

CVE-2026-54275 (aiohttp) affects the aiohttp package prior to 3.14.1. The issue is a TLS server_hostname SNI check bypass that occurs when an existing connection is reused for multiple requests with different per-request server_hostname values. As a result, later requests to the same domain may r...

UBUNTU-CVE-2026-6734

Impact: When using Socks5ProxyAgent, undici reuses a single connection pool across different origins without verifying that the pool's origin matches the requested origin. All requests are dispatched through the pool connected to the first origin, regardless of the intended destination. This caus...

CVE-2026-6734

Impact: When using Socks5ProxyAgent, undici reuses a single connection pool across different origins without verifying that the pool's origin matches the requested origin. All requests are dispatched through the pool connected to the first origin, regardless of the intended destination. This caus...

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...