CVE-2026-55733
Gravedad CVSS v4.0:
MEDIA
Tipo:
No Disponible / Otro tipo
Fecha de publicación:
01/08/2026
Última modificación:
01/08/2026
Descripción
*** Pendiente de traducción *** Allocation of Resources Without Limits or Throttling in ueberauth guardian allows denial of service via unbounded atom creation from attacker-controlled binary input.<br />
<br />
Guardian.Permissions.AtomEncoding encodes permission scopes by passing arbitrary binaries to String.to_atom/1. When encode/3 in lib/guardian/permissions/atom_encoding.ex is called with a list, each binary entry is handled by the encode_value/3 binary clause, which calls String.to_atom(value) with no allow-list check. The perm_set argument (the application&#39;s small, finite set of legitimate permission names) is discarded, so any external string flows straight into atom creation. This encoder is selected with use Guardian.Permissions, encoding: Guardian.Permissions.AtomEncoding and reached through the imported encode/3 entry point.<br />
<br />
String.to_atom/1 creates a brand-new atom for every previously unseen binary, atoms are never garbage collected, and the BEAM atom table is fixed at roughly 1,048,576 entries by default. An application that funnels attacker-influenced permission scopes (from a request body, a JWT claim, or other external input) into encode/3 therefore mints one permanent atom per distinct value. A modest stream of varied, unauthenticated input permanently consumes the atom table and crashes the BEAM node with system_limit, taking down every application running on it.<br />
<br />
The default encoder is Guardian.Permissions.BitwiseEncoding, which is not affected.<br />
<br />
This issue affects guardian: from 2.0.0 before 2.4.1.
Impacto
Puntuación base 4.0
6.90
Gravedad 4.0
MEDIA



