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.
Weakness
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.
Affected products
- benoitc hackney
References
- https://cna.erlef.org/cves/CVE-2026-47067.html
- https://github.com/benoitc/hackney/commit/31f6f0e27e096ad88743dfded4f030a3ee74972e
- https://github.com/benoitc/hackney/security/advisories/GHSA-9653-rcfr-5c62
- https://osv.dev/vulnerability/EEF-CVE-2026-47067
- https://github.com/benoitc/hackney/security/advisories/GHSA-9653-rcfr-5c62
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