Atom table exhaustion via unrecognized URL schemes in hackney (benoitc hackney)
At a glance
- Source
- NVD
- EPSS
- EPSS 0.75 % · percentile 55 ()
- State
- PUBLISHED
- Published
- Updated
- Assigner
- EEF
- NVD status
- Analyzed
Description
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.
Weaknesses (CWE)
- CWE-770 — Allocation of Resources Without Limits or Throttling
References
Scores
| Version | Score | Vector | Scored by |
|---|---|---|---|
| CVSS 4.0 | HIGH 8.7 | 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 | EEF |
| CVSS 4.0 | HIGH 8.7 | 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 | NVD · 6b3ad84c-e1a6-4bf7-a703-f496b71e49db (Secondary) |
| CVSS 3.1 | HIGH 7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H | NVD · nvd@nist.gov (Primary) |
European references
- ENISA EUVD · EUVD-2026-31691
- GCVE · GCVE-0-2026-47067
Affected configurations (NVD CPE)
cpe:2.3:a:benoitc:hackney:*:*:*:*:*:*:*:*≥ 2.0.0 < 4.0.1
Affected products
| Product | Versions |
|---|---|
| benoitc · hackney | affected 2.0.0 < 4.0.1 |
| benoitc · hackney | affected d9713695c0d99855d12c73fd8a0b4be0543950c4 < 31f6f0e27e096ad88743dfded4f030a3ee74972e |
Sources
| Source | Licence |
|---|---|
| CVE List (CVEProject cvelistV5) | CVE Program Terms of Use |
| EPSS (FIRST.org) | FIRST — attribution requested |
| ENISA EUVD | ENISA — reproduction authorised, source acknowledged |
| NVD (NIST) via fkie-cad/nvd-json-data-feeds | Public domain — this product uses data from the NVD API but is not endorsed or certified by the NVD |