Review reviewHigh

CVE-2026-47073

benoitc hackney

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; beca...

CVSS
8.7
EPSS
0.85%
54.7% percentile
CISA KEV
Not listed
Published
2026.05.26
PRIORITY ASSESSMENT

Review review

The CVSS severity warrants an early asset and exposure review.

Known exploitationNot established by KEV
Exploit probability0.85%
Technical severityCVSS 8.7

Vulnerability overview

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; beca...

Affected product and versions

Product
benoitc hackney
Affected versions
>= 2.0.0 < 4.0.1, >= 690cecaf236fba49526da404a5bc889a24367a3e < ce0109e2970ace6e20ff29bae9d05c3ac22ec6dc
Fixed versions
4.0.1

Recommended response sequence

Confirm exposure before applying a vendor-supported change.

Full remediation guide
  1. 1
    Identify

    Confirm that benoitc hackney and an affected version are present.

  2. 2
    Prioritize

    Combine exploitation signals with asset exposure and business criticality.

  3. 3
    Remediate

    Follow the vendor advisory or supported update path and preserve rollback options.

  4. 4
    Verify

    Recheck the version, service health, access paths, and relevant logs.

Technical data

CVSS vector
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
CWE
CWE-400