CVE-2026-12523: Uncontrolled Resource Consumption

Summary Cloudflare quiche's HTTP/3 layer was discovered to be vulnerable to resource exhaustion i.e., memory by means of specially crafted HTTP/3 frames. Impact HTTP/3 defines multiple frame types to support HTTP message exchanges and connection management. Each frame has a length and a payload...

CVE-2026-55213: Memory Allocation with Excessive Size Value

h2o is an HTTP server with support for HTTP/1.x, HTTP/2 and HTTP/3. Prior to commit edd7a120bfc4af11ac0cbebce2a43cc1f93f9af1, when h2o processes a QPACK instruction sent from the peer over HTTP/3, lib/http3/qpack.c might allocate an on-stack buffer as large as approximately 800 KB by calling...

CVE-2026-11352: Loop with Unreachable Exit Condition

An issue in curl’s QUIC UDP receive function allows a malicious HTTP/3 server to trigger a remote denial of service against a curl or libcurl client. Because the helper function discards zero-length UDP datagrams before counting them toward the per-call packet budget, a connected QUIC peer can...

CVE-2026-9545: Exposure of Sensitive Information to an Unauthorized Actor

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uses a proper HTTP/3 server for the initial transfers, and when it makes a second transfer to the same site it has been replaced by the attacker's impostor machine - without a valid certificate.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-2026-54772

Name of the Vulnerable Software and Affected Versions erlang quic versions prior to 1.4.4 Description The QUIC client fails to authenticate the server during the TLS 1.3 handshake. Specifically, the CertificateVerify signature is not checked, the certificate chain is not validated, and the hostna...

CVE-2026-48743: Inconsistent Interpretation of HTTP Requests

Envoy is an open source edge and service proxy designed for cloud-native applications. Prior to 1.35.11, 1.36.7, 1.37.3, and 1.38.1, Envoy can translate a downstream HTTP/3 request that is complete at the transport layer HEADERS with FIN / headers-only close but still carries a nonzero...

CVE-2026-40211: Allocation of Resources Without Limits or Throttling

An attacker can send crafted DNS over HTTP/3 queries, triggering an exception that prevents some buffer from being freed right away. The buffer will be freed at the end of the QUIC connection, but on some setups it might be possible to open enough concurrent DoH3 streams to trigger an out-of-memo...

CVE-2026-53622: Authentication Bypass Using an Alternate Path or Channel

Traefik is an HTTP reverse proxy and load balancer. Versions prior to 3.7.3, 3.6.18, and 2.11.51 have 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...

CVE-2026-42530: Use After Free

NGINX Open Source has a vulnerability in the ngxhttpv3module module. When NGINX Open Source is configured to use the HTTP/3 QUIC module, a remote unauthenticated attacker along with conditions beyond their control can use a specially crafted HTTP/3 session to reopen a QPACK encoder stream. This m...

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...

CVE-2026-48748: Allocation of Resources Without Limits or Throttling

Netty is a network application framework for development of protocol servers and clients. Starting in version 4.2.0.Final and prior to version 4.2.15.Final, a memory exhaustion vulnerability in the Netty HTTP/3 codec allows the creation of an infinite number of blocked streams, which can cause OO...

CVE-2026-44892: Uncontrolled Resource Consumption

Netty is a network application framework for development of protocol servers and clients. Prior to version 4.2.15.Final, the default configuration of the Http3ConnectionHandler in the Netty HTTP/3 codec lacks an enforced maximum header size limit. When a peer does not explicitly specify...

Linux Distros Unpatched Vulnerability : CVE-2026-40898

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available. - quic-go is an implementation of the QUIC protocol in Go. Prior to version 0.59.1, an attacker can cause excessive memory allocation in quic-go's HTTP/3 client a...

CVE-2026-40898

quic-go is an implementation of the QUIC protocol in Go. Prior to version 0.59.1, an attacker can cause excessive memory allocation in quic-go's HTTP/3 client and server implementations by sending a QPACK-encoded HEADERS frame that decodes into a large trailer field section with many unique field...

CVE-2026-40898: Allocation of Resources Without Limits or Throttling

quic-go is an implementation of the QUIC protocol in Go. Prior to version 0.59.1, an attacker can cause excessive memory allocation in quic-go's HTTP/3 client and server implementations by sending a QPACK-encoded HEADERS frame that decodes into a large trailer field section with many unique field...

CVE-2026-47070

Sensitive Data Exposure vulnerability in benoitc hackney allows Retrieve Embedded Sensitive Data. The HTTP/3 redirect handler in src/hackneyh3.erl passes the original request headers unchanged to the redirect target without performing any cross-origin check. When a client issues an HTTP/3 request...

CVE-2026-47077 Unbounded body accumulation in HTTP/3 response loop in hackney

Allocation of Resources Without Limits or Throttling vulnerability in benoitc hackney allows Flooding. hackneyh3:awaitresponseloop/6 accumulates the HTTP/3 response body in memory without any size cap. The after Timeout clause is a per-message inactivity timer that resets on every received chunk,...

CVE-2026-47070: URL Redirection to Untrusted Site

Sensitive Data Exposure vulnerability in benoitc hackney allows Retrieve Embedded Sensitive Data. The HTTP/3 redirect handler in src/hackneyh3.erl passes the original request headers unchanged to the redirect target without performing any cross-origin check. When a client issues an HTTP/3 request...

CVE-2026-47077: Uncontrolled Resource Consumption

Allocation of Resources Without Limits or Throttling vulnerability in benoitc hackney allows Flooding. hackneyh3:awaitresponseloop/6 accumulates the HTTP/3 response body in memory without any size cap. The after Timeout clause is a per-message inactivity timer that resets on every received chunk,...

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...