CVE-2026-8469 – Unauthenticated denial-of-service via BEAM atom table exhaustion in phoenix_storybook

CVE ID :CVE-2026-8469

Published : May 20, 2026, 2:17 p.m. | 40 minutes ago

Description :Allocation of Resources Without Limits or Throttling vulnerability in phenixdigital phoenix_storybook allows unauthenticated denial-of-service via BEAM atom table exhaustion.

Multiple LiveView event handlers convert user-supplied event parameter strings to atoms using String.to_atom/1 without validation: ‘Elixir.PhoenixStorybook.ExtraAssignsHelpers’:handle_set_variation_assign/3 interns every key of the psb-assign params map; ‘Elixir.PhoenixStorybook.ExtraAssignsHelpers’:handle_toggle_variation_assign/3 interns the “attr” value from psb-toggle events; ‘Elixir.PhoenixStorybook.ExtraAssignsHelpers’:to_variation_id/2 interns elements of “variation_id”; and ‘Elixir.PhoenixStorybook.ExtraAssignsHelpers’:to_value/4 interns raw string values for attributes declared as :atom or :boolean. BEAM atoms are never garbage-collected, so each unique attacker-controlled string is a permanent allocation. Once the atom table ceiling (~1,048,576 atoms) is reached, the entire BEAM node aborts, taking down all applications running on it.

This issue affects phoenix_storybook from 0.2.0 before 1.1.0.

Severity: 8.2 | HIGH

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