CVE-2026-47071
SOCKS5 TLS upgrade ignores caller timeout in hackney
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.
INFO
Published Date :
May 25, 2026, 3:16 p.m.
Last Modified :
May 27, 2026, 1:56 p.m.
Remotely Exploit :
Yes !
Source :
6b3ad84c-e1a6-4bf7-a703-f496b71e49db
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | HIGH | [email protected] | ||||
| CVSS 4.0 | HIGH | 6b3ad84c-e1a6-4bf7-a703-f496b71e49db | ||||
| CVSS 4.0 | HIGH | 6b3ad84c-e1a6-4bf7-a703-f496b71e49db |
Solution
- Update hackney to version 4.0.1 or later.
- Ensure TLS connections respect configured timeouts.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-47071.
| URL | Resource |
|---|---|
| https://cna.erlef.org/cves/CVE-2026-47071.html | Third Party Advisory Patch |
| https://github.com/benoitc/hackney/commit/5ccdab725c561a6f03d05a51f2d0664f98236dae | Patch |
| https://github.com/benoitc/hackney/security/advisories/GHSA-gp9c-pm5m-5cxr | Exploit Patch Vendor Advisory |
| https://osv.dev/vulnerability/EEF-CVE-2026-47071 | Third Party Advisory Patch |
| https://github.com/benoitc/hackney/security/advisories/GHSA-gp9c-pm5m-5cxr | Exploit Patch Vendor Advisory |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-47071 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-47071
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-47071 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-47071 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
Initial Analysis by [email protected]
May. 27, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Added CPE Configuration OR *cpe:2.3:a:benoitc:hackney:*:*:*:*:*:*:*:* versions from (including) 0.10.0 up to (excluding) 4.0.1 Added Reference Type EEF: https://cna.erlef.org/cves/CVE-2026-47071.html Types: Patch, Third Party Advisory Added Reference Type EEF: https://github.com/benoitc/hackney/commit/5ccdab725c561a6f03d05a51f2d0664f98236dae Types: Patch Added Reference Type CISA-ADP: https://github.com/benoitc/hackney/security/advisories/GHSA-gp9c-pm5m-5cxr Types: Exploit, Patch, Vendor Advisory Added Reference Type EEF: https://github.com/benoitc/hackney/security/advisories/GHSA-gp9c-pm5m-5cxr Types: Exploit, Patch, Vendor Advisory Added Reference Type EEF: https://osv.dev/vulnerability/EEF-CVE-2026-47071 Types: Patch, Third Party Advisory -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
May. 26, 2026
Action Type Old Value New Value Added Reference https://github.com/benoitc/hackney/security/advisories/GHSA-gp9c-pm5m-5cxr -
New CVE Received by 6b3ad84c-e1a6-4bf7-a703-f496b71e49db
May. 25, 2026
Action Type Old Value New Value Added 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. Added CVSS V4.0 AV:N/AC:L/AT:P/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 Added CWE CWE-400 Added Reference https://cna.erlef.org/cves/CVE-2026-47071.html Added Reference https://github.com/benoitc/hackney/commit/5ccdab725c561a6f03d05a51f2d0664f98236dae Added Reference https://github.com/benoitc/hackney/security/advisories/GHSA-gp9c-pm5m-5cxr Added Reference https://osv.dev/vulnerability/EEF-CVE-2026-47071