8.7

CVE-2026-47067: Atom table exhaustion via unrecognized URL schemes in hackney

Analyzed
Published 25-05-2026Last modified 27-05-2026

Vulnerability summary

CVE-2026-47067 is a high (CVSS 8.7) vulnerability in benoitc hackney. EPSS estimates a 0.75% chance of exploitation in the next 30 days, higher than 55.1% of scored vulnerabilities. 1 public exploit is recorded.

Priority
Prioritisepublic exploit

Public exploit (GitHub, Date unknown)

Source freshness unavailable

How is this decided?
CVSS score
8.7/10
010
High · v4.0 (CVE.org)
EPSS score
0.75%
0%100%
Low · +0.05 pp in 30 days
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits1github

Timeline

  1. 25-05-2026
    PublishedVulnerability first disclosed.
  2. 27-05-2026
    Last modifiedVulnerability information updated.

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.

CVSS metrics

3 scores · 2 sources · 2 versions

EPSS trend

Probability

0.75%

Chance of exploitation in the next 30 days

Percentile

55%

Versus all other CVEs

30-day change

Increase +0.05 pp

From 0.70% on 04-10-2026

04-10-202603-11-2026

Known exploited

Compare KEV catalogs
CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

1 found
  • githubUnverified

    Hackney

    Maturity: poc

Weaknesses

CWE · root cause

Affected systems

Version check

Known conditions: network-reachable, no authentication, no user interaction (CVSS vector). Other conditions: not stated in public data.

Benoitc1 product
  • hackney≥ d9713695c0d99855d12c73fd8a0b4be0543950c4, < 31f6f0e27e096ad88743dfded4f030a3ee74972e | ≥ 2.0.0, < 4.0.1

1 vendor · 1 product

References

4 links