CVE-2026-32688

Published: Apr 27, 2026 Last Modified: Apr 27, 2026
ExploitDB:
Other exploit source:
Google Dorks:
HIGH 8,7
Source: 6b3ad84c-e1a6-4bf7-a703-f496b71e49db
Attack Vector: network
Attack Complexity: low
Privileges Required: none
User Interaction: none
Confidentiality: N/A
Integrity: N/A
Availability: N/A

Description

AI Translation Available

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.

EPSS (Exploit Prediction Scoring System)

Trend Analysis

EPSS (Exploit Prediction Scoring System)

Prevede la probabilità di sfruttamento basata su intelligence sulle minacce e sulle caratteristiche della vulnerabilità.

EPSS Score
0,0013
Percentile
0,3th
Updated

EPSS Score Trend (Last 2 Days)

770

Allocation of Resources Without Limits or Throttling

Incomplete
Abstraction: Base Structure: Simple
Common Consequences
Security Scopes Affected:
Availability
Potential Impacts:
Dos: Resource Consumption (Cpu) Dos: Resource Consumption (Memory) Dos: Resource Consumption (Other)
Applicable Platforms
All platforms may be affected
Likelihood of Exploit: High
View CWE Details
https://cna.erlef.org/cves/CVE-2026-32688.html
https://cna.erlef.org/cves/CVE-2026-32688.html
https://github.com/elixir-plug/plug_cowboy/commit/bfb34cb45…
https://github.com/elixir-plug/plug_cowboy/commit/bfb34cb45eb354e56437f7023fb30…
https://github.com/elixir-plug/plug_cowboy/security/advisor…
https://github.com/elixir-plug/plug_cowboy/security/advisories/GHSA-q8x4-x7mp-5…
https://osv.dev/vulnerability/EEF-CVE-2026-32688
https://osv.dev/vulnerability/EEF-CVE-2026-32688