CVE-2026-47073

HIGH EPSS 52.8%
Published May 25, 20261mo ago · Modified Jun 17, 20261w ago
8.7 CVSS 4.0
High
Find Similar
Published May 25, 2026 1mo ago
Last Modified Jun 17, 2026 1w ago

Description

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.

CVSS Details

Base Score
8.7
Exploitability
—
Impact
—
Vector string
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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Attack Vector Network
Attack Complexity Low
Privileges Required None
User Interaction None
Scope X

Threat Intelligence

EPSS Exploit Probability
52.8% percentile
Exploit & Patch Status
Public Exploit Known
Patch Available

Weaknesses 1

CWE-400 Uncontrolled Resource Consumption Resource Mgmt

Affected Products 1

VendorProductVersionRange
benoitchackney*≥2.0.0  –  <4.0.1

References 4

  • cna.erlef.org https://cna.erlef.org/cves/CVE-2026-47073.html
    PatchThird Party Advisory
  • github.com https://github.com/benoitc/hackney/commit/ce0109e2970ace6e20ff29bae9d05c3ac22ec6dc
    Patch
  • github.com https://github.com/benoitc/hackney/security/advisories/GHSA-q8jg-fgj4-fphf
    ExploitPatchVendor Advisory
  • osv.dev https://osv.dev/vulnerability/EEF-CVE-2026-47073
    PatchThird Party Advisory

Remediation

  • cna.erlef.org https://cna.erlef.org/cves/CVE-2026-47073.html
    PatchThird Party Advisory
  • github.com https://github.com/benoitc/hackney/commit/ce0109e2970ace6e20ff29bae9d05c3ac22ec6dc
    Patch
  • github.com https://github.com/benoitc/hackney/security/advisories/GHSA-q8jg-fgj4-fphf
    ExploitPatchVendor Advisory
  • osv.dev https://osv.dev/vulnerability/EEF-CVE-2026-47073
    PatchThird Party Advisory