CVE-2026-47067highCWE-770

CVE-2026-47067: high-severity vulnerability in benoitc hackney

Atom table exhaustion via unrecognized URL schemes in hackney

Published · Updated

Follow this CVE+ Monitor hackney+ Monitor hackney

E-mail alert when it lands in KEV, gets a public PoC or its score goes up.

21Vexday Risk Score

No sign of exploitation. No public exploitation artifact known so far.

ssvc Trackcvss 8.7epss 0.8%
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.
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
Affected products
benoitc · hackney
Related CVEs — benoitc hackney

In the same product, most dangerous first.

CVE-2026-47073HIGHUnbounded memory consumption in WebSocket client in hackneyEPSS 0.9%CVE-2026-47071HIGHSOCKS5 TLS upgrade ignores caller timeout in hackneyEPSS 0.8%CVE-2026-47066HIGHInfinite loop in Alt-Svc header parser in hackneyEPSS 0.8%CVE-2026-47077HIGHUnbounded body accumulation in HTTP/3 response loop in hackneyEPSS 0.7%CVE-2026-97200HIGHUnbounded response body buffering and decompression in hackneyEPSS 0.6%CVE-2026-47072MEDIUMCRLF injection in WebSocket upgrade request in hackneyEPSS 0.5%