PT-2026-43065 · Benoitc · Hackney

Benoit Chesneau + 2 · Published 2026-05-25 · Updated 2026-05-25 · CVE-2026-47067

Mitre

CVSS v4.0

8.7

High

Base vector

AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

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.

Fix

Allocation of Resources Without Limits

Weakness Enumeration

CWE-770

Related Identifiers

CVE-2026-47067

Affected Products

Hackney

References · 4

• https://github.com/benoitc/hackney/commit/31f6f0e27e096ad88743dfded4f030a3ee74972e · Patch
• https://github.com/benoitc/hackney/security/advisories/GHSA-9653-rcfr-5c62 · Vendor Advisory
• https://osv.dev/vulnerability/EEF-CVE-2026-47067 · Note
• https://cna.erlef.org/cves/CVE-2026-47067.html · Note