CVE-2026-54894 — Security Box Score

CVE · referencelatest edition

Reference page — cumulative record through Wednesday, August 19, 2026 UTC. Reference pages update as the archive grows; only dated daily editions are immutable pages of record.

CVE-2026-54894MEDIUM

ueberauth guardian — Atom-table exhaustion denial of service in Guardian via unbounded atom creation from binary keys

  AV  AC  AT  PR  UI  VC  VI  VA   CVSS    EPSS   %ile   KEV
   L   L   P   N   N   N   N   H    6.9   .0027   19.4     —

AFFECTED
  Product   Versions                                    Fixed
  guardian  0.1.0 –                                     —
  guardian  7126fa433afc2563fcac0c9aa35193965f8fd5f8 –  —

TIMELINE
  Jun 16  Reserved by EEF
  Aug 1   EXPLOIT PUBLISHED — CVE-2026-54894 (ueberauth guardian). Public exploit reference added.
  Aug 1   Published (CNA: EEF)
  Aug 6   EXPLOIT PUBLISHED — CVE-2026-54894 (ueberauth guardian). Public exploit reference added.

CWE-770 · CNA: EEF · CVSS v4.0 · 4 references · NVD status: Analyzed

Description

Allocation of Resources Without Limits or Throttling in ueberauth guardian allows denial of service via unbounded atom creation from attacker-influenced binary input. Guardian.Plug.Keys derives connection and session namespace keys by passing arbitrary binaries to String.to_atom/1. base_key/1 in lib/guardian/plug/keys.ex converts any binary into the atom :"guardian_<input>", and the derived helpers claims_key/1, resource_key/1, and token_key/1 create a second atom on top of that. key_from_other/1 likewise converts a regex-captured binary through String.to_atom/1. The public specs advertise String.t() as a valid argument, so passing a string is documented usage, and higher-level entry points such as Guardian.Plug.current_token(conn, key: key) thread the caller-supplied key straight into these functions. 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 routes attacker-influenced data (a tenant identifier, header, or other request input) into a Guardian key 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, taking down every application running on it. This issue affects guardian: from 0.1.0 before 2.4.1.

Lifecycle

Complete event history — 4 events, chronological
Date	Event	Detail
June 16, 2026	Reserved	Reserved by EEF
August 1, 2026	EXPLOIT PUBLISHED	EXPLOIT PUBLISHED — CVE-2026-54894 (ueberauth guardian). Public exploit reference added.
August 1, 2026	Published	Published (CNA: EEF)
August 6, 2026	EXPLOIT PUBLISHED	EXPLOIT PUBLISHED — CVE-2026-54894 (ueberauth guardian). Public exploit reference added.

Affected

Affected products and packages — 2 rows
Vendor	Product / Package	Ecosystem	Version introduced	Fixed
ueberauth	guardian	—	0.1.0	—
ueberauth	guardian	—	7126fa433afc2563fcac0c9aa35193965f8fd5f8	—

Weaknesses

CWE-770

References (4)

https://cna.erlef.org/cves/CVE-2026-54894.html [Third Party Advisory]
https://github.com/ueberauth/guardian/commit/2952657e42e6341a67e6aaad09d8f0b40ae917cb [Patch]
https://github.com/ueberauth/guardian/security/advisories/GHSA-xqch-c77q-rgh5 [Exploit, Patch, Vendor Advisory]
https://osv.dev/vulnerability/EEF-CVE-2026-54894 [Third Party Advisory]

Authoritative record: CVE-2026-54894 at cve.org

Vendors: ueberauth

Weaknesses: CWE-770

About this page

This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2026-54894 from the CVE Program record, NVD enrichment, the CISA KEV catalog, EPSS, and OSV advisories. The box score's numbers (CVSS, EPSS, KEV status) are current as of Wednesday, August 19, 2026 UTC and are re-derived as the archive grows; only dated daily editions are immutable pages of record. The authoritative source for this identifier is cve.org.