CVE-2026-47067

HIGH

Atom table exhaustion via unrecognized URL schemes in hackney

Title source: cna
STIX 2.1

Description

Allocation of Resources Without Limits or Throttling vulnerability in benoitc hackney allows Flooding. The URL parser in src/hackney_url.erl converts every unrecognized URL scheme to a permanent BEAM atom via binary_to_atom/2. BEAM atoms are never garbage-collected and the atom table defaults to a hard limit of 1,048,576 entries. An attacker who can supply URLs with attacker-chosen scheme prefixes — directly as request targets, as configured webhook URLs, or via Location headers followed during redirects — can exhaust the atom table and crash the entire BEAM VM with system_limit. This issue affects hackney: from 2.0.0 before 4.0.1.

Scores

CVSS v3 7.5
EPSS 0.0067
EPSS Percentile 47.0%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CISA SSVC

Vulnrichment
Exploitation poc
Automatable yes
Technical Impact partial

Details

CWE
CWE-770
Status published
Products (2)
benoitc/hackney 2.0.0 - 4.0.1 (2 CPE variants)
benoitc/hackney d9713695c0d99855d12c73fd8a0b4be0543950c4 - 31f6f0e27e096ad88743dfded4f030a3ee74972e
Published May 25, 2026
Tracked Since May 25, 2026