8.2

CVE-2026-47071: SOCKS5 TLS upgrade ignores caller timeout in hackney

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

Vulnerability summary

CVE-2026-47071 is a high (CVSS 8.2) Uncontrolled Resource Consumption 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
8.2/10
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

Uncontrolled Resource Consumption vulnerability in benoitc hackney allows Flooding. The SOCKS5 transport in src/hackney_socks5.erl correctly applies the caller-supplied timeout to the SOCKS5 negotiation phase, but then upgrades the connection to TLS using the two-argument form ssl:connect/2, which defaults to an infinite timeout. The Timeout value is in scope at the call site but is not forwarded. A hostile SOCKS5 proxy that completes the SOCKS5 handshake normally and then goes silent (or sends a partial TLS ServerHello and stalls) will cause the connecting process to block indefinitely, regardless of the connect_timeout or recv_timeout options supplied by the caller. This issue affects hackney: from 0.10.0 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≥ 34cdbd1d20a282aacc286a89327465a3925b4c5d, < 5ccdab725c561a6f03d05a51f2d0664f98236dae | ≥ 0.10.0, < 4.0.1

1 vendor · 1 product

References

4 links