CVE-2026-71554

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...

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...

EUVD-2026-51078

A flaw was found in Dogtag PKI's ACME responder where the HTTP-01 challenge validator accepts IP address literals as dns identifiers and follows HTTP redirects without validating that the target is a public address. An unauthenticated ACME account holder can exploit this to perform server-side...

UBUNTU-CVE-2026-58153

Apache Traffic Server forwards HTTP/2 origin trailers to HTTP/1 clients without proper chunked framing when converting HTTP/2 to HTTP/1. This issue affects Apache Traffic Server: from 10.0.0 through 10.1.3. Users are recommended to upgrade to version 9.2.15 or 10.1.4, which fix the issue...

CVE-2026-58153

CVE-2026-58153 affects Apache Traffic Server (versions 10.0.0 through 10.1.3). The issue arises when converting HTTP/2 to HTTP/1: origin trailers are forwarded to HTTP/1 clients without proper chunked framing. This can lead to unsafe trailer handling during protocol translation. Remediation: upgr...

PT-2026-65067

Name of the Vulnerable Software and Affected Versions facil.io versions 0.7.5 through 0.7.6 Description A denial-of-service issue exists in the HTTP/1.1 chunked transfer encoding parser. An unauthenticated remote attacker can crash the server by sending a single POST request with a...

GHSA-MHVJ-JHPQ-885V blaze: Multiple HTTP/1.1 request-smuggling primitives in blaze's Java wire parser

Summary Five independent HTTP/1.1 conformance laxities in blaze's hand-written Java parser http/src/main/java/org/http4s/blaze/http/parser/ cause request-boundary disagreement with a stricter intermediary. All are reachable from a default BlazeServerBuilder with no non-default configuration. Impa...

CVE-2026-59249 Sign-tolerant HTTP/1 chunk-size parser in Mint enables response smuggling against strict intermediaries on pooled connections

Inconsistent interpretation of HTTP requests HTTP response smuggling vulnerability in elixir-mint mint allows a malicious HTTP/1 server to desynchronize a strict intermediary and the Mint client on the same pooled connection, enabling response-queue poisoning against subsequent requests that shar...

CVE-2026-56810

Allocation of Resources Without Limits or Throttling vulnerability in elixir-mint mint Mint.HTTP1 module allows a denial of service via an oversized chunked transfer-encoded response. This vulnerability is associated with program files lib/mint/http1.ex and program routines...

CVE-2026-48743

Envoy (open source edge/service proxy) contains a HTTP/3 to HTTP/1 request smuggling vulnerability prior to versions 1.35.11, 1.36.7, 1.37.3, and 1.38.1. A downstream HTTP/3 request that is complete at the transport layer with a nonzero Content-Length can be mistranslated into a complete upstream...

CVE-2026-48743

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-2026-48743 Envoy: HTTP/3 to HTTP/1 request smuggling via headers-only request with nonzero Content-Length

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...

netty: io.netty/netty-codec-http: Netty: HTTP Request Smuggling due to improper handling of conflicting HTTP/1.0 headers

A flaw was found in Netty's HttpObjectDecoder. A remote attacker can exploit this by sending a specially crafted HTTP/1.0 request that includes both Transfer-Encoding: chunked and Content-Length headers. While Netty correctly strips the conflicting Content-Length header for HTTP/1.1 messages, thi...

netty: io.netty/netty-codec-http: Netty: HTTP Request Smuggling due to improper handling of conflicting HTTP/1.0 headers

A flaw was found in Netty's HttpObjectDecoder. A remote attacker can exploit this by sending a specially crafted HTTP/1.0 request that includes both Transfer-Encoding: chunked and Content-Length headers. While Netty correctly strips the conflicting Content-Length header for HTTP/1.1 messages, thi...

CVE-2026-49753 HTTP response smuggling in Mint HTTP/1 client via lenient Content-Length parsing

Inconsistent Interpretation of HTTP Requests 'HTTP Request/Response Smuggling' vulnerability in elixir-mint Mint allows attacker-controlled HTTP/1 servers to desynchronise response framing on shared connections. Mint's HTTP/1 Content-Length parser, Mint.HTTP1.Parse.contentlengthheader/1 in...

EEF-CVE-2026-49753 HTTP response smuggling in Mint HTTP/1 client via lenient Content-Length parsing

Summary Inconsistent Interpretation of HTTP Requests 'HTTP Request/Response Smuggling' vulnerability in elixir-mint Mint allows attacker-controlled HTTP/1 servers to desynchronise response framing on shared connections. Mint's HTTP/1 Content-Length parser, Mint.HTTP1.Parse.content\length\header/1...

[SECURITY] Fedora 43 Update: perl-Starman-0.4018-1.fc43

Starman is a PSGI perl web server that has unique features such as high performance, preforking, use of signals and a small memory footprint. It is P SGI compatible and offers HTTP/1.1 support...

CVE-2026-5052 Vault Vulnerable to Server-Side Request Forgery in ACME Challenge Validation via Attacker-Controlled DNS

Vault’s PKI engine’s ACME validation did not reject local targets when issuing http-01 and tls-alpn-01 challenges. This may lead to these requests being sent to local network targets, potentially leading to information disclosure. Fixed in Vault Community Edition 2.0.0 and Vault Enterprise 2.0.0,...

EUVD-2026-21738

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...

CVE-2026-2835

An HTTP Request Smuggling vulnerability CWE-444 has been found in Pingora's parsing of HTTP/1.0 and Transfer-Encoding requests. The issue occurs due to improperly allowing HTTP/1.0 request bodies to be close-delimited and incorrect handling of multiple Transfer-Encoding values, allowing attackers...