EEF-CVE-2026-8468

Summary

Allocation of Resources Without Limits or Throttling vulnerability in plug_project plug allows denial of service via unbounded buffer accumulation in multipart header parsing.

'Elixir.Plug.Conn':readpartheaders/2 in lib/plug/conn.ex does not obey its :length parameter. There is no upper bound on the size of the accumulated buffer. By contrast, the sibling function readpartbody has an explicit bytesize(acc) > length guard that stops accumulation once a limit is reached. No such guard exists in readpart_headers. An unauthenticated remote attacker can exhaust server memory by sending a crafted multipart/form-data request, causing a denial of service.

This issue affects plug from 1.4.0 before 1.15.4, 1.16.3, 1.17.1, 1.18.2, and 1.19.2.

Configuration

The application must use Plug.Parsers with the :multipart parser, or otherwise call Plug.Conn.readpartheaders/2 to process multipart/form-data request bodies. Deployments that do not handle multipart uploads are not affected.