Description
Allocation of Resources Without Limits or Throttling vulnerability in elixir-plug plug_cowboy allows unauthenticated remote denial of service via atom table exhaustion. Plug.Cowboy.Conn.conn/1 in lib/plug/cowboy/conn.ex calls String.to_atom/1 on the value returned by :cowboy_req.scheme/1. For HTTP/2 connections, cowlib passes the client-supplied :scheme pseudo-header value through verbatim without validation. Each unique value permanently allocates a new entry in the BEAM atom table. Since atoms are never garbage-collected and the atom table has a fixed limit (default 1,048,576), an unauthenticated attacker can exhaust the table by sending HTTP/2 requests with unique :scheme values, causing the Erlang VM to abort with system_limit and taking down the entire node. This vulnerability does not affect HTTP/1.1, where cowboy derives the scheme from the listener type rather than from a client-supplied header. This issue affects plug_cowboy: from 2.0.0 before 2.8.1.
INFO
Published Date :
2026-04-27T13:45:35.160Z
Last Modified :
2026-04-29T17:08:07.227Z
Source :
EEF
AFFECTED PRODUCTS
The following products are affected by CVE-2026-32688 vulnerability.
| Vendors | Products |
|---|---|
| Elixir-plug |
|
REFERENCES
Here, you will find a curated list of external links that provide in-depth information to CVE-2026-32688.
