Resource exhaustion in Benoitc Hackney

CVE-2026-47067

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.

EPSS: 0.008 (52.6th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

Affected products

  • Benoitc Hackney — versions 2.0.0, d9713695c0d99855d12c73fd8a0b4be0543950c4

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-47067?
CVE-2026-47067 is a high-severity vulnerability in Benoitc Hackney, classified under Allocation of Resources Without Limits or Throttling. CVSS score: 7.5/10. Published 2026-05-25.
How severe is CVE-2026-47067?
High severity. CVSS v3 base score is 7.5 out of 10.