CVE-2026-47067
HighPublic exploitAtom table exhaustion via unrecognized URL schemes in hackney
Published May 25, 2026 · Updated Oct 8, 2026 · Also known as EEF-CVE-2026-47067, EUVD-2026-31691, GHSA-9653-rcfr-5c62
Key Facts
Patch immediately- CVE-2026-47067 is a high-severity vulnerability (CVSS 8.7 v4) affecting Hackney (Benoitc).
- It is not listed in any known-exploited vulnerabilities catalog. Public exploit code is available.
- EPSS estimates a 0.7% probability of exploitation in the next 30 days.
- Fixed versions are available, including Hackney 31f6f0e27e096ad88743dfded4f030a3ee74972e, Hackney 4.0.1.
- Brandefense priority: patch immediately, because public exploit code exists for a high-severity flaw.
CVSS v4
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
EPSS (30-day exploit likelihood)
0.7%
Exploited in the wild
No known
Not in a known-exploited catalog
Public exploit code
Available
Proof-of-concept or weaponized module
Get the full CVE-2026-47067 brief as a PDF
Every affected product and fixed release, exploitation status and a first 24 hours response checklist, emailed within minutes.
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.
Affected Products
3 affected entries in total| Product | Affected versions | Fixed in |
|---|---|---|
| HackneyBenoitc | >= 2.0.0 | 4.0.1 |
Patched Releases
Hackney
31f6f0e27e096ad88743dfded4f030a3ee74972e, 4.0.1
Timeline
Publicly disclosed
May 25, 2026
Last updated
Oct 8, 2026
Weakness Type
- CWE-770 Allocation of Resources Without Limits or Throttling
References
- advisoryGHSA advisory
- advisoryhttps://github.com/benoitc/hackney/security/advisories/GHSA-9653-rcfr-5c62
- advisoryhttps://github.com/CVEProject/cvelistV5/tree/main/cves/2026/47xxx/CVE-2026-47067.json
- advisoryhttps://nvd.nist.gov/vuln/detail/CVE-2026-47067
- patchhttps://github.com/benoitc/hackney/commit/31f6f0e27e096ad88743dfded4f030a3ee74972e
FAQ
Common Questions.
Allocation of Resources Without Limits or Throttling vulnerability in benoitc hackney allows Flooding.
Affected: Hackney (Benoitc) versions >= 2.0.0. The full list is in the CVE brief.
It is not listed in any known-exploited vulnerabilities catalog.
No, it is not currently listed in the CISA Known Exploited Vulnerabilities catalog.
Public exploit code is available.
Fixed versions are available, including Hackney 31f6f0e27e096ad88743dfded4f030a3ee74972e, Hackney 4.0.1.
Brandefense priority: patch immediately, because public exploit code exists for a high-severity flaw.
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