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

Summary

CVECVE-2026-8469
StatePUBLISHED
AssignerEEF
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-05-20 14:17:04 UTC
Updated2026-05-21 15:16:30 UTC
DescriptionAllocation 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.

Risk And Classification

Primary CVSS: v4.0 8.2 HIGH from 6b3ad84c-e1a6-4bf7-a703-f496b71e49db

CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

EPSS: 0.000560000 probability, percentile 0.174990000 (date 2026-05-27)

Problem Types: CWE-770 | CWE-770 CWE-770 Allocation of Resources Without Limits or Throttling


VersionSourceTypeScoreSeverityVector
4.06b3ad84c-e1a6-4bf7-a703-f496b71e49dbSecondary8.2HIGHCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/C...
4.0CNACVSS8.2HIGHCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

CVSS v4.0 Breakdown

Attack Vector
Network
Attack Complexity
Low
Attack Requirements
Present
Privileges Required
None
User Interaction
None
Confidentiality
None
Integrity
None
Availability
High
Sub Conf.
None
Sub Integrity
None
Sub Availability
None

CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Phenixdigital Phoenix Storybook affected 0.2.0 1.1.0 semver Not specified
CNA Phenixdigital Phoenix Storybook affected 0228669d55c23a754d1ef11f49a32121129d5395 96d524690af0fe197a49f60d18e564a620b9ef81 git Not specified

References

ReferenceSourceLinkTags
cna.erlef.org/cves/CVE-2026-8469.html 6b3ad84c-e1a6-4bf7-a703-f496b71e49db cna.erlef.org
github.com/phenixdigital/phoenix_storybook/security/advisories/GHSA-833p... 134c704f-9b21-4f2e-91b3-4a467353bcc0 github.com
osv.dev/vulnerability/EEF-CVE-2026-8469 6b3ad84c-e1a6-4bf7-a703-f496b71e49db osv.dev
github.com/phenixdigital/phoenix_storybook/commit/96d524690af0fe197a49f6... 6b3ad84c-e1a6-4bf7-a703-f496b71e49db github.com
CVE Program record CVE.ORG www.cve.org canonical
NVD vulnerability detail NVD nvd.nist.gov canonical, analysis

Vendor Comments And Credit

Discovery Credit

CNA: Peter Ullrich (en)

CNA: Christian Blavier (en)

CNA: Jonatan Männchen (en)

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