CVE-2026-32688
CVE.org · Published
- Record status
- Published
- Identifier year (not publication year)
- 2026
- Source publication
- Source updated
- Imported by cveboard
- Source snapshot
- cve_2026-10-24_midnight_baseline ·
CNA source text (English)
Atom table exhaustion via HTTP/2 :scheme pseudo-header in plug_cowboy
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.
Scoped product and version facts
Fix information unknown; no fixed version is derived here. Missing information does not prove that no fix exists.
Exploitation unknown; this catalogue does not assess exploitation.
plug_cowboy
- Vendor
- elixir-plug
- Product
- plug_cowboy
- Platforms
- Unknown
- Default status
unaffected- Package
- plug_cowboy
- Package collection
- https://repo.hex.pm
| Version (version) | Status (status) | Version scheme (versionType) | Exclusive end (lessThan) | Inclusive end (lessThanOrEqual) | Status changes (at → status) |
|---|---|---|---|---|---|
| 2.0.0 | affected | semver | 2.8.1 | Unavailable | None listed |
plug_cowboy
- Vendor
- elixir-plug
- Product
- plug_cowboy
- Platforms
- Unknown
- Default status
unaffected- Package
- elixir-plug/plug_cowboy
- Package collection
- https://github.com
| Version (version) | Status (status) | Version scheme (versionType) | Exclusive end (lessThan) | Inclusive end (lessThanOrEqual) | Status changes (at → status) |
|---|---|---|---|---|---|
| 12ecfd024bb179d48b018fecf074e43fe6a19c83 | affected | git | bfb34cb45eb354e56437f7023fb306de1bf9c19b | Unavailable | None listed |