CVE-2026-55733Public exploitHinoki check available

Node crash via unbounded atom creation

Published Aug 1, 2026 · Updated Aug 1, 2026

Denial of service in ueberauth Guardian 2.0.0 through 2.4.0 allows attackers to crash a BEAM node via crafted permission scopes. Guardian.Permissions.AtomEncoding.encode_value/3 passes arbitrary binary values to String.to_atom/1 while ignoring its permission allow-list. Exposure requires the non-default AtomEncoding encoder and attacker-influenced encode/3 input; atom-table exhaustion terminates every application on the node.

CVSS severity6.9
Medium
EPSS probability0.32%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Denial of service in ueberauth Guardian 2.0.0 through 2.4.0 allows attackers to crash a BEAM node via crafted permission scopes. Guardian.Permissions.AtomEncoding.encode_value/3 passes arbitrary binary values to String.to_atom/1 while ignoring its permission allow-list. Exposure requires the non-default AtomEncoding encoder and attacker-influenced encode/3 input; atom-table exhaustion terminates every application on the node.

The record

CVE
CVE-2026-55733
Published
Aug 1, 2026
Updated
Aug 1, 2026
Vendor
ueberauth
Product
Guardian
Classifications
CWE-770, CAPEC-130, T1499.004
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 1, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 1, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=2.0.0 <2.4.1
  2. Affected versionversion=b7a6128ca4d0ffb7f7df5219dd982304ff9d6802 <9cd268557846aa4c3ad53566c08f2c190ee5513f

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

ueberauth · Guardianversion=2.0.0 <2.4.1; version=b7a6128ca4d0ffb7f7df5219dd982304ff9d6802 <9cd268557846aa4c3ad53566c08f2c190ee5513f

Published CVSS scores

7.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
6.9GitHubCVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-770Allocation of Resources Without Limits or Throttling
CAPEC-130Excessive Allocation
T1499.004Application or System Exploitation

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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