EEF-CVE-2026-47073

Source
https://cna.erlef.org/osv/EEF-CVE-2026-47073.html
Import Source
https://cna.erlef.org/osv/EEF-CVE-2026-47073.json
JSON Data
https://api.osv.dev/v1/vulns/EEF-CVE-2026-47073
Aliases
  • CVE-2026-47073
  • GHSA-q8jg-fgj4-fphf
Published
2026-05-25T14:00:49.112Z
Modified
2026-05-25T14:26:25.912821920Z
Severity
  • 8.7 (High) CVSS_V4 - 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 CVSS Calculator
Summary
Unbounded memory consumption in WebSocket client in hackney
Details

Summary

Allocation of Resources Without Limits or Throttling vulnerability in benoitc hackney allows Flooding. The WebSocket client in src/hackneyws.erl imposes no upper bound on memory consumption in three code paths. First, readhandshakeresponse/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, parsepayload/9 and parseactivepayload/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 fragbuffer field in #wsdata{} 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.

Database specific
{
    "cpe_ids": [
        "cpe:2.3:a:benoitc:hackney:*:*:*:*:*:*:*:*"
    ],
    "cwe_ids": [
        "CWE-400"
    ],
    "capec_ids": [
        "CAPEC-125"
    ]
}
References
Credits
    • Peter Ullrich - FINDER
    • Benoit Chesneau - REMEDIATION_DEVELOPER
    • Jonatan Männchen - ANALYST

Affected packages

Hex / hackney

Package

Name
hackney
Purl
pkg:hex/hackney

Affected ranges

Type
SEMVER
Events
Introduced
2.0.0
Fixed
4.0.1

Affected versions

2.*
2.0.0
2.0.1
3.*
3.0.0
3.0.1
3.0.2
3.0.3
3.1.0
3.1.1
3.1.2
3.2.0
3.2.1
4.*
4.0.0

Database specific

source
"https://cna.erlef.org/osv/EEF-CVE-2026-47073.json"

Git / github.com/benoitc/hackney

Affected ranges

Type
GIT
Repo
https://github.com/benoitc/hackney
Events

Database specific

source
"https://cna.erlef.org/osv/EEF-CVE-2026-47073.json"