CVE-2026-33871

CVE-2026-33871 affects Netty, an asynchronous event-driven network framework. The issue occurs when a remote attacker floods an HTTP/2 server with CONTINUATION frames, exploiting an unlimited frame-count and bypassing size-based mitigations with zero-byte frames. This can cause high CPU usage and...

CVE-2025-57804 h2 allows HTTP Request Smuggling due to illegal characters in headers

h2 is a pure-Python implementation of a HTTP/2 protocol stack. Prior to version 4.3.0, an HTTP/2 request splitting vulnerability allows attackers to perform request smuggling attacks by injecting CRLF characters into headers. This occurs when servers downgrade HTTP/2 requests to HTTP/1.1 without...

HTTP/2: Multiple HTTP/2 enabled web servers are vulnerable to a DDoS attack (Rapid Reset Attack)

A flaw was found in handling multiplexed streams in the HTTP/2 protocol. A client can repeatedly make a request for a new multiplex stream and immediately send an RSTSTREAM frame to cancel it. This creates extra work for the server setting up and tearing down the streams while not hitting any...

golang: net/http: handle server errors after sending GOAWAY

A flaw was found in the golang package. In net/http in Go, attackers can cause a denial of service because an HTTP/2 connection can hang during closing if a fatal error preempts the shutdown...

AZL-33607 CVE-2021-44716 affecting package libcontainers-common for versions less than 20210626-3

net/http in Go before 1.16.12 and 1.17.x before 1.17.5 allows uncontrolled memory consumption in the header canonicalization cache via HTTP/2 requests...

tomcat: specially crafted sequence of HTTP/2 requests can lead to DoS

A specially crafted sequence of HTTP/2 requests sent to Apache Tomcat 10.0.0-M1 to 10.0.0-M5, 9.0.0.M1 to 9.0.35 and 8.5.0 to 8.5.55 could trigger high CPU usage for several seconds. If a sufficient number of such requests were made on concurrent HTTP/2 connections, the server could become...

httpd: mod_http2: DoS via slow, unneeded request bodies

In Apache HTTP server versions 2.4.37 and prior, by sending request bodies in a slow loris way to plain resources, the h2 stream for that request unnecessarily occupied a server thread cleaning up that incoming data. This affects only HTTP/2 modhttp2 connections...

HTTP/2: flood using HEADERS frames results in unbounded memory growth

A flaw was found in HTTP/2. Using HEADER frames with invalid HTTP headers and queuing of response RSTSTREAM frames, an attacker could cause a flood resulting in unbounded memory growth. The highest threat from this vulnerability is to system availability...

DEBIAN-CVE-2019-10079

Apache Traffic Server is vulnerable to HTTP/2 setting flood attacks. Earlier versions of Apache Traffic Server didn't limit the number of setting frames sent from the client using the HTTP/2 protocol. Users should upgrade to Apache Traffic Server 7.1.7, 8.0.4, or later versions...

HTTP/2: large amount of data requests leads to denial of service

A flaw was found in HTTP/2. An attacker can request a large amount of data by manipulating window size and stream priority to force the server to queue the data in 1-byte chunks. Depending on how efficiently this data is queued, this queue can consume excess CPU, memory, or both, leading to a...

HTTP/2: flood using HEADERS frames results in unbounded memory growth

A flaw was found in HTTP/2. Using HEADER frames with invalid HTTP headers and queuing of response RSTSTREAM frames, an attacker could cause a flood resulting in unbounded memory growth. The highest threat from this vulnerability is to system availability...