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

Official 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.

Affected products (as reported)

References

• https://github.com/phenixdigital/phoenix_storybook/security/advisories/GHSA-833p-95jq-929q vendor-advisory, related
• https://cna.erlef.org/cves/CVE-2026-8469.html related
• https://osv.dev/vulnerability/EEF-CVE-2026-8469 related
• https://github.com/phenixdigital/phoenix_storybook/commit/96d524690af0fe197a49f60d18e564a620b9ef81 patch