Vulnerability · CVE-2026-47073
Allocation of Resources Without Limits or Throttling vulnerability in benoitc hackney allows Flooding.
Published May 25, 2026 · corrected/updated Jul 24, 2026 · benoitc hackney · evidence confidence high
Allocation of Resources Without Limits or Throttling vulnerability in benoitc hackney allows Flooding. The WebSocket client in src/hackney_ws.erl imposes no upper bound on memory consumption in three code paths. First, read_handshake_response/3 accumulates received bytes into a growing buffer with no size cap; the per-receive timeout resets on every chunk, so a server that streams bytes without ever sending \r\n\r\n causes the buffer to grow until memory is exhausted. Second, parse_payload/9 and parse_active_payload/8 do not validate the declared frame payload length against any limit; because RFC 6455 allows payload lengths up to 2^63-1 bytes, a server that announces a very large frame and dribbles bytes causes the accumulation buffer to grow until OOM. Third, the frag_buffer field in #ws_data{} accumulates continuation frames indefinitely; a server that sends an endless stream of non-final (nofin) fragmented frames without ever sending a final (fin) frame grows frag_buffer without bound. In all three cases the attacker only needs to control the WebSocket server the hackney client connects to, with no authentication or special client configuration required. This issue affects hackney: from 2.0.0 before 4.0.1.
Grounded briefings
Catalog interpretations for three audiences. Each brief cites ingested metadata and the original advisories below. They are not independent research and they do not invent exploit steps.
Executive
CVE-2026-47073 is a high public vulnerability record for benoitc hackney. It is not currently listed in the CISA Known Exploited catalog. Check the linked vendor or CERT advisories for patch status. This summary is a catalog interpretation of the ingested metadata and cites the original advisories below.
System administrator
Identify whether benoitc hackney is in your estate, then compare installed versions with the affected ranges. Affected packages or ranges on record: benoitc/hackney. Check the linked vendor or CERT advisories for patch status. Prefer the vendor or distribution advisory linked in Sources before changing production systems. This is a catalog interpretation, not a runbook.
Security analyst
Signals on file: CVSS 8.7, EPSS 0.8%. It is not currently listed in the CISA Known Exploited catalog. Weakness classes: CWE-400. Sources contributing to this record: cve_org, epss, nvd. Public exploit references, when present, are outbound links only and are not proof of active exploitation. This is a catalog interpretation of stored metadata.
Exploitation and remediation
Exploitation evidence
Not listed as known exploited in CISA KEV. Not in CISA KEV or VulnCheck KEV.
Patch and remediation
No required-action text is stored yet. Use the vendor or CERT links in Sources for patch availability.
Safe detection guidance
Compare installed versions with the affected ranges below and verify the advisory from the original publisher. This site stores metadata and outbound links only; it does not ship exploit code or proof-of-concept payloads.
Code
The project this record applies to. Exploit listings stay in References.
Timeline
Detection, updates, and resolution for this record.
May 25, 2026 · NIST NVD
Detected
Allocation of Resources Without Limits or Throttling vulnerability in benoitc hackney allows Flooding. The WebSocket client in src/hackney_ws.erl imposes no upper bound on memory consumption in three code paths. First, read_handshake_response/3 accumulates received bytes into a growing buffer with no size cap; the per-receive timeout resets on every chunk, so a server that streams bytes without ev
Jul 24, 2026 · NIST NVD
Updated
Allocation of Resources Without Limits or Throttling vulnerability in benoitc hackney allows Flooding. The WebSocket client in src/hackney_ws.erl imposes no upper bound on memory consumption in three code paths. First, read_handshake_response/3 accumulates received bytes into a growing buffer with no size cap; the per-receive timeout resets on every chunk, so a server that streams bytes without ev
Affected
- cpe benoitc/hackneyversion unspecified
Sources
- CVE.orgVulnerability recordCVE-2026-47073
Official CVE identifier
cve.org - FIRST EPSSExploitation probabilityCVE-2026-47073
30-day exploitation probability 0.8%
first.org - NIST NVDVulnerability recordCVE-2026-47073
Allocation of Resources Without Limits or Throttling vulnerability in benoitc hackney allows Flooding. The WebSocket client in src/hackney_ws.erl imposes no upper bound on memory consumption in three code paths. First, read_handshake_response/3 accumulates received bytes into a g
nvd.nist.gov