cowboy: Cowboy: Denial of Service via HTTP/1.1 duplicate header names

A flaw was found in Cowboy. An unauthenticated remote attacker can exploit this vulnerability by sending multiple HTTP/1.1 header lines with the same name. This bypasses the maxheaders limit, causing the connection process memory to grow uncontrollably. This can lead to memory exhaustion and a...

CVE-2026-65624 Cowboy HTTP/1.1 max_headers Bypass via Duplicate Header Names Enables Memory Exhaustion

Allocation of Resources Without Limits or Throttling vulnerability in ninenines cowboy allows an unauthenticated remote attacker to exhaust connection process memory over HTTP/1.1. The HTTP/1.1 handler in cowboyhttp enforces the maxheaders limit by counting the number of distinct header names in ...

CVE-2026-65624

The CVE affects the Cowboy HTTP/1.1 handler. The root cause is a per-request header handling flaw: when a request uses repeated header names, values are concatenated into a single binary under one map key, so the max_headers limit never increases and the total header block can grow without bound....

CVE-2026-53426 Atom-table exhaustion denial-of-service via JSON parse_document in MDEx

Allocation of Resources Without Limits or Throttling vulnerability in leandrocp MDEx allows Excessive Allocation. MDEx.parsedocument/2 accepts a :json, json source. In lib/mdex.ex, the private jsontonode/1 function passes the attacker-controlled nodetype value to Module.concat/1, which calls...

GHSA-Q8X4-X7MP-5VG2 Plug.Cowboy vulnerable to unauthenticated remote DoS via HTTP/2 `:scheme` atom-table exhaustion

Summary An unauthenticated remote denial-of-service vulnerability in Plug.Cowboy.Conn allows any attacker who can reach an HTTPS Plug.Cowboy listener via HTTP/2 to permanently exhaust the BEAM atom table and crash the entire Erlang VM. Am I Affected? All users running plugcowboy with HTTP/2 may b...

[SECURITY] Fedora 37 Update: elixir-1.14.2-1.fc37

Elixir is a programming language built on top of the Erlang VM. As Erlang, it is a functional language built to support distributed, fault-tolerant, non-stop applications with hot code swapping...