actix-http has HTTP/1.1 CL.TE Request Smuggling

A vulnerability in actix-http's HTTP/1.1 request parser allows an unauthenticated remote client to smuggle requests in deployments where a front-end HTTP intermediary and the Actix backend disagree about whether Content-Length or Transfer-Encoding: chunked defines the request body length. Severit...

Important: Red Hat Security Advisory: nghttp2 security update

An update for nghttp2 is now available for Red Hat Enterprise Linux 9.0 Update Services for SAP Solutions. Red Hat Product Security has rated this update as having a security impact of Important. A Common Vulnerability Scoring System CVSS base score, which gives a detailed severity rating, is...

RHEL 8 : nghttp2 (RHSA-2026:8541)

The remote Redhat Enterprise Linux 8 host has a package installed that is affected by a vulnerability as referenced in the RHSA-2026:8541 advisory. libnghttp2 is a library implementing the Hypertext Transfer Protocol version 2 HTTP/2 protocol in C. Security Fixes: nghttp2: nghttp2: Denial of...

EUVD-2026-21997

An issue was discovered in HAProxy before 3.3.6. The HTTP/3 parser does not check that the received body length matches a previously announced content-length when the stream is closed via a frame with an empty payload. This can cause desynchronization issues with the backend server and could be...

ALSA-2026:7666 Important: nghttp2 security update

libnghttp2 is a library implementing the Hypertext Transfer Protocol version 2 HTTP/2 protocol in C. Security Fixes: nghttp2: nghttp2: Denial of Service via malformed HTTP/2 frames after session termination CVE-2026-27135 For more details about the security issues, including the impact, a CVSS...

CVE-2026-40396

Varnish Cache 9 before 9.0.1 allows a "workspace overflow" denial of service daemon panic after timeoutlinger. A malicious client could send an HTTP/1 request, wait long enough until the session releases its worker thread timeoutlinger and resume traffic before the session is closed timeoutidle...

UBUNTU-CVE-2026-40394

Varnish Cache 9 before 9.0.1 and Varnish Enterprise before 6.0.16r11 allows a "workspace overflow" denial of service daemon panic for certain amounts of prefetched data. The setup of an HTTP/2 session starts with a speculative HTTP/1 transport, and upon upgrading to h2 the HTTP/1 request is...

Node.js: Node.js: Memory leak and Denial of Service via crafted HTTP/2 WINDOW_UPDATE frames

A flaw was found in Node.js. A remote attacker can exploit this vulnerability in Node.js HTTP/2 servers by sending specially crafted WINDOWUPDATE frames on stream 0 connection-level. These frames can cause the flow control window to exceed its maximum value, leading to a memory leak as Http2Sessi...

BIT-NODE-MIN-2026-21714

A memory leak occurs in Node.js HTTP/2 servers when a client sends WINDOWUPDATE frames on stream 0 connection-level that cause the flow control window to exceed the maximum value of 2³¹-1. The server correctly sends a GOAWAY frame, but the Http2Session object is never cleaned up. This vulnerabili...

SUSE CVE-2026-34475

Varnish Cache before 8.0.1 and Varnish Enterprise before 6.0.16r12, in certain unchecked req.url scenarios, mishandle URLs with a path of / for HTTP/1.1, potentially leading to cache poisoning or authentication bypass...

CVE-2026-31935

A flaw was found in Suricata. A remote attacker can exploit this vulnerability by sending a flood of crafted HTTP2 continuation frames. This can lead to memory exhaustion, causing the Suricata process to shut down, resulting in a Denial of Service DoS. Mitigation To mitigate this issue, consider...

CVE-2026-34441 cpp-httplib: HTTP Request Smuggling via Unconsumed GET Request Body

cpp-httplib is a C++11 single-file header-only cross platform HTTP/HTTPS library. Prior to version 0.40.0, cpp-httplib is vulnerable to HTTP Request Smuggling. The server's static file handler serves GET responses without consuming the request body. On HTTP/1.1 keep-alive connections, the unread...

CVE-2026-34475

A flaw was found in Varnish Cache and Varnish Enterprise. A remote attacker could exploit this vulnerability by sending specially crafted HTTP/1.1 requests with a path of / in the URL. This mishandling of URLs, specifically in unchecked req.url scenarios, could lead to cache poisoning, where an...

CVE-2026-33870

Netty is an asynchronous, event-driven network application framework. In versions prior to 4.1.132.Final and 4.2.10.Final, Netty incorrectly parses quoted strings in HTTP/1.1 chunked transfer encoding extension values, enabling request smuggling attacks. Versions 4.1.132.Final and 4.2.10.Final fi...

CVE-2026-33871

Netty is an asynchronous, event-driven network application framework. In versions prior to 4.1.132.Final and 4.2.10.Final, a remote user can trigger a Denial of Service DoS against a Netty HTTP/2 server by sending a flood of CONTINUATION frames. The server's lack of a limit on the number of...

UBUNTU-CVE-2026-34475

Varnish Cache before 8.0.1 and Varnish Enterprise before 6.0.16r12, in certain unchecked req.url scenarios, mishandle URLs with a path of / for HTTP/1.1, potentially leading to cache poisoning or authentication bypass...

CVE-2026-34475

Varnish Cache before 8.0.1 and Varnish Enterprise before 6.0.16r12, in certain unchecked req.url scenarios, mishandle URLs with a path of / for HTTP/1.1, potentially leading to cache poisoning or authentication bypass...

SUSE SLES12 Security Update : tomcat (SUSE-SU-2026:1058-1)

The remote SUSE Linux SLES12 host has packages installed that are affected by multiple vulnerabilities as referenced in the SUSE-SU-2026:1058-1 advisory. Update to Tomcat 9.0.115: - CVE-2025-48989: HTTP/2 protocol including DNS over HTTPS is vulnerable to 'MadeYouReset' DoS attack bsc1243895. -...

GHSA-W9FJ-CFPG-GRVV Netty HTTP/2 CONTINUATION Frame Flood DoS via Zero-Byte Frame Bypass

Summary A remote user can trigger a Denial of Service DoS against a Netty HTTP/2 server by sending a flood of CONTINUATION frames. The server's lack of a limit on the number of CONTINUATION frames, combined with a bypass of existing size-based mitigations using zero-byte frames, allows an user to...

EUVD-2026-15756

Mattermost versions 11.4.x = 11.4.0, 11.3.x = 11.3.1, 11.2.x = 11.2.3, 10.11.x = 10.11.11 fail to rate limit login requests which allows unauthenticated remote attackers to cause denial of service server crash and restart via HTTP/2 single packet attack with 100+ parallel login requests...