CVE-2026-71554 h2: Duplicate Host header could facilitate request smuggling

h2 is a pure-Python implementation of a HTTP/2 protocol stack. Versions up to and including 4.4.0 accept request header blocks containing more than one Host header, and forward every Host header to the consuming application. Where the consumer downgrades HTTP/2 to HTTP/1.1, the resulting request...

netty-codec-haproxy: Netty HAProxy PROXY protocol v2 codec: Denial of Service via memory leak from crafted PROXY protocol headers

A flaw was found in the Netty HAProxy PROXY protocol v2 codec. A remote attacker can exploit this vulnerability by sending a specially crafted HAProxy PROXY protocol v2 header with nested PP2TYPESSL type-length-value TLV records. This can lead to a memory leak, causing the underlying cumulation...

MongoDB 8.0.x < 8.0.28 / 8.3.x < 8.3.7 Multiple Vulnerabilities (SERVER-124355)

The version of MongoDB installed on the remote host is 8.0.x prior to 8.0.28 or 8.3.x prior to 8.3.7. It is, therefore, affected by multiple vulnerabilities: - Using expressions that generate large arrays it is possible to craft a query that creates very large intermediate objects in memory,...

EUVD-2026-50207

Apache Traffic Server reuses multiplexed HTTP/2 origin connections without verifying the server certificate covers the new request hostname. This issue affects Apache Traffic Server: from 9.0.0 through 9.2.14, from 10.0.0 through 10.1.3. Users are recommended to upgrade to version 9.2.15 or 10.1....

CVE-2026-58150

Summary: Apache Traffic Server is vulnerable to HTTP/2 downgrade request smuggling because it does not reject Transfer-Encoding in HTTP/2 requests. Affected versions: 8.0.0–8.1.9, 9.0.0–9.2.14, 10.0.0–10.1.3. Impact: Verified issue exists; CVSS metrics indicate HIGH severity with network attack v...

CVE-2026-55851

A flaw was found in Netty's codec-haproxy module. A remote attacker could exploit a vulnerability in the HAProxyMessageDecoder by sending a specially crafted PROXY protocol v2 message. This leads to unbounded buffer accumulation, causing a denial of service DoS due to memory exhaustion...

CVE-2026-64785

SwiftNIO HTTP/2 was missing validation on inbound HEADERS frames that let CR, LF, NUL, SP and other control characters reach an HTTP/1.1 backend through NIOHTTP2's HTTP/2-to-HTTP/1 codec, enabling HTTP request smuggling or response splitting. This vulnerability is addressed in swift-nio-http2...

CVE-2026-13067 tlsCATrusts Role Restriction Not Enforced via PROXY Protocol v2 on Unix Domain Socket

When PROXY protocol v2 is used on the Unix domain socket path, roles derived from X.509 client certificates may not be validated against the configured tlsCATrusts allow-list. This can result in unintended role assignments following MONGODB-X509 authentication. Affected scenarios require local...

CVE-2026-13067

Technical details for CVE-2026-13067 are not publicly available in the provided documents; monitor for updates.

tlsCATrusts Role Restriction Not Enforced via PROXY Protocol v2 on Unix Domain Socket

When PROXY protocol v2 is used on the Unix domain socket path, roles derived from X.509 client certificates may not be validated against the configured tlsCATrusts allow-list. This can result in unintended role assignments following MONGODB-X509 authentication. Affected scenarios require local...

EUVD-2026-46679

Vulnerability in the Oracle Coherence product of Oracle Fusion Middleware component: Core. Supported versions that are affected are 14.1.1.0.0, 14.1.2.0.0 and 15.1.1.0.0. Easily exploitable vulnerability allows unauthenticated attacker with network access via HTTP/2 to compromise Oracle Coherence...

dotnet: SocketsHttpHandler Http2Connection - HTTP/2 SETTINGS/PING ACK flood causing OOM

.NET Denial of Service Vulnerability - HTTP/2 SETTINGS/PING ACK flood causing OOM...

CVE-2026-54340

h2o is an HTTP server with support for HTTP/1.x, HTTP/2 and HTTP/3. Prior to commit 9265bdd, there is an HTTP/2 state amplification issue that combines HPACK decompression amplification with Slowloris-style stream stalling. Amplified decoded header state can be retained by stalled HTTP/2 streams,...

UBUNTU-CVE-2026-54340

h2o is an HTTP server with support for HTTP/1.x, HTTP/2 and HTTP/3. Prior to commit 9265bdd, there is an HTTP/2 state amplification issue that combines HPACK decompression amplification with Slowloris-style stream stalling. Amplified decoded header state can be retained by stalled HTTP/2 streams,...

CVE-2026-48068

@grpc/grps-js implements the core functionality of gRPC purely in JavaScript, without a C++ addon. Prior to 1.9.16, 1.10.12, 1.11.4, 1.12.7, 1.13.5, and 1.14.4, an invalid incoming HTTP/2 stream initiation can cause a server process created using @grpc/grpc-js to crash. This issue is fixed in...

CVE-2026-6790

In Eclipse Jetty, for HTTP/1, HTTP/2 and HTTP/3 requests, there is no strict check that the request authority host and port matches what provided in the Host header if present. This was not enforced in earlier HTTP RFC for example, in RFC 2616, but it is in the latest RFC 9110 and 9112. This...

EEF-CVE-2026-59246 Zero-length HTTP/2 CONTINUATION frames bypass Mint's header-block byte-size cap and exhaust client memory

Summary Allocation of resources without limits vulnerability in elixir-mint mint allows a remote HTTP/2 server to exhaust memory on the client host and cause a denial of service. The Mint.HTTP2.handle\continuation/3 function in lib/mint/http2.ex accumulates the header-block fragment carried by ea...

CVE-2026-55233 OpenResty: Buffer overflow when writing PROXY protocol v2 header to upstream

OpenResty is a high performance web platform. From 1.29.2.1 to before 1.29.2.5, an out-of-bounds write vulnerability exists in the upstream PROXY protocol v2 implementation. When OpenResty is configured to send PROXY protocol version 2 headers to upstream servers, constructing the header in the...

netty-codec-haproxy: Netty HAProxy PROXY protocol v2 codec: Denial of Service via memory leak from crafted PROXY protocol headers

A flaw was found in the Netty HAProxy PROXY protocol v2 codec. A remote attacker can exploit this vulnerability by sending a specially crafted HAProxy PROXY protocol v2 header with nested PP2TYPESSL type-length-value TLV records. This can lead to a memory leak, causing the underlying cumulation...

CVE-2026-13474

Denial of service via malformed HTTP/2 requests in NetScaler ADC and NetScaler Gateway if HTTP/2 is enabled in HTTP Profile and associated with the virtual server of type LB, CS, VPN or the service configured on NetScaler...