[ CVE-2026-115274 · Published 30 Oct 2026 ]

Vulnerability in elixir-lang elixir

CVSS 6.9 EPSS <1%No fix listed yet

[ Why it matters ]Priority signals

  • Public proof-of-concept exploit exists (CISA SSVC)

[ Description ]Official description

Improper Validation of Specified Quantity in Input vulnerability in the Elixir standard library's JSON module allows an unauthenticated attacker who supplies a JSON document to cause a denial of service through CPU and memory exhaustion. JSON.decode/1 and JSON.decode!/1 convert each integer literal with erlang:binary_to_integer/1 and do not bound its length. A literal of one million digits decodes successfully but costs 100 to 300 times as much CPU as a string of the same length, so one request body of a few megabytes holds a scheduler for about a second. A literal of more than about 1.29 million digits raises SystemLimitError. Applications generated by phx.new decode request bodies with JSON in Plug.Parsers, before routing and authentication. This issue affects elixir: from 1.18.0-rc.0 before 1.18.6, from 1.19.0-rc.0 before 1.19.7, and from 1.20.0-rc.0 before 1.20.5.

[ Fixes ]Fixes and patches

No fix or interim patch is linked from our sources yet. Check the vendor references below and limit exposure of affected systems until a fix is available.