CVE-2026-9545 exposing HTTP/3 early data

In this scenario, libcurl first uses a proper HTTP/3 server for the initial transfers, and when it makes a second transfer to the same site it has been replaced by the attacker's impostor machine - without a valid certificate. When libcurl returns to the hostname the second time with a cached SSL...

CVE-2026-9545 exposing HTTP/3 early data

In this scenario, libcurl first uses a proper HTTP/3 server for the initial transfers, and when it makes a second transfer to the same site it has been replaced by the attacker's impostor machine - without a valid certificate. When libcurl returns to the hostname the second time with a cached SSL...

Curl 8.11.0 < 8.21.0 HTTP/3 Early Data Information Disclosure

The version of curl installed on the remote host is 8.11.0 prior to 8.21.0. It is, therefore, affected by an information disclosure vulnerability: - When libcurl returns to a hostname with a cached SSL session and early data enabled, libcurl might send the request bytes before enforcing the...

UBUNTU-CVE-2026-9545

In this scenario, libcurl first uses a proper HTTP/3 server for the initial transfers, and when it makes a second transfer to the same site it has been replaced by the attacker's impostor machine - without a valid certificate. When libcurl returns to the hostname the second time with a cached SSL...

CVE-2026-9545

In this scenario, libcurl first uses a proper HTTP/3 server for the initial transfers, and when it makes a second transfer to the same site it has been replaced by the attacker's impostor machine - without a valid certificate. When libcurl returns to the hostname the second time with a cached SSL...

exposing HTTP/3 early data

In this scenario, libcurl first uses a proper HTTP/3 server for the initial transfers, and when it makes a second transfer to the same site it has been replaced by the attacker's impostor machine - without a valid certificate. When libcurl returns to the hostname the second time with a cached SSL...

CURL-CVE-2026-9545 exposing HTTP/3 early data

In this scenario, libcurl first uses a proper HTTP/3 server for the initial transfers, and when it makes a second transfer to the same site it has been replaced by the attacker's impostor machine - without a valid certificate. When libcurl returns to the hostname the second time with a cached SSL...

PT-2026-51754

Name of the Vulnerable Software and Affected Versions libcurl affected versions not specified Description An issue exists where libcurl may send request data on a new connection before enforcing certificate verification failure. This occurs when a user first connects to a legitimate HTTP/3 server...

curl: CVE-2026-9545: exposing HTTP/3 early data

Summary: When the ngtcp2 HTTP/3 backend reuses a TLS session that advertises early data support, cfngtcp2onsessionreuse initializes the HTTP/3 connection state and marks the connection filter as connected before the new QUIC/TLS handshake has completed. The request send path can then reach...

JLSEC-2026-249 Issue summary: Some non-default TLS server configurations can cause unbounded memory growth when...

Issue summary: Some non-default TLS server configurations can cause unbounded memory growth when processing TLSv1.3 sessions Impact summary: An attacker may exploit certain server configurations to trigger unbounded memory growth that would lead to a Denial of Service This problem can occur in...

SUSE CVE-2025-64763

Envoy is a high-performance edge/middle/service proxy. In 1.33.12, 1.34.10, 1.35.6, 1.36.2, and earlier, when Envoy is configured in TCP proxy mode to handle CONNECT requests, it accepts client data before issuing a 2xx response and forwards that data to the upstream TCP connection. If a forwardi...

CVE-2025-64763

A flaw was found in Envoy. This vulnerability allows a de-synchronized CONNECT tunnel state via accepting client data before issuing a 2xx response and forwarding it to the upstream TCP Transmission Control Protocol connection when configured in TCP Transmission Control Protocol proxy mode to...

BIT-ENVOY-2025-64763 Envoy forwards early CONNECT data in TCP proxy mode

Envoy is a high-performance edge/middle/service proxy. In 1.33.12, 1.34.10, 1.35.6, 1.36.2, and earlier, when Envoy is configured in TCP proxy mode to handle CONNECT requests, it accepts client data before issuing a 2xx response and forwards that data to the upstream TCP connection. If a forwardi...

EUVD-2025-201099

Envoy forwards early CONNECT data in TCP proxy mode...

CVE-2025-64763 Envoy forwards early CONNECT data in TCP proxy mode

Envoy is a high-performance edge/middle/service proxy. In 1.33.12, 1.34.10, 1.35.6, 1.36.2, and earlier, when Envoy is configured in TCP proxy mode to handle CONNECT requests, it accepts client data before issuing a 2xx response and forwards that data to the upstream TCP connection. If a forwardi...

CVE-2025-64763 Envoy forwards early CONNECT data in TCP proxy mode

Envoy is a high-performance edge/middle/service proxy. In 1.33.12, 1.34.10, 1.35.6, 1.36.2, and earlier, when Envoy is configured in TCP proxy mode to handle CONNECT requests, it accepts client data before issuing a 2xx response and forwards that data to the upstream TCP connection. If a forwardi...

CVE-2025-64763

Envoy CVE-2025-64763 relates to a de-synchronization risk in TCP proxy mode where Envoy may accept client data for CONNECT requests before sending a 2xx response, and then forward that data to the upstream connection. If the upstream proxy returns a non‑2xx status, the CONNECT tunnel state can be...

CVE-2024-45397

h2o is an HTTP server with support for HTTP/1.x, HTTP/2 and HTTP/3. When an HTTP request using TLS/1.3 early data on top of TCP Fast Open or QUIC 0-RTT packets is received and the IP-address-based access control is used, the access control does not detect and prohibit HTTP requests conveyed by...

Lightning-Fast Requests with Early Data

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DEBIAN-CVE-2024-45397

h2o is an HTTP server with support for HTTP/1.x, HTTP/2 and HTTP/3. When an HTTP request using TLS/1.3 early data on top of TCP Fast Open or QUIC 0-RTT packets is received and the IP-address-based access control is used, the access control does not detect and prohibit HTTP requests conveyed by...