CVE-2026-47071

SOCKS5 TLS upgrade ignores caller timeout in hackney

HIGH
7.5
CVSS Score
Published: May 25, 2026 at 02:00 PM UTC
Updated: July 24, 2026 at 10:23 AM UTC
1 product affected across 1 vendorHackney

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Severity
HIGH7.5
Exploit prediction
EPSS 0.8%
SSVC
PoC

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

0.10.0 ≤ v < 4.0.10.10.034cdbd1d20a282aacc286a89327465a3925b4c5d
Vendor states this is fixed in 5ccdab725c561a6f03d05a51f2d0664f98236dae (fixed)
Affected range stops below 4.0.1, so it looks safe — our inference, not a vendor statement

References (4)

Vendor AdvisoryRelatedExploitPatch
Source: cverecord
https://github.com/benoitc/hackney/security/advisories/GHSA-gp9c-pm5m-5cxr
RelatedPatchThird Party Advisory
Source: cverecord
https://cna.erlef.org/cves/CVE-2026-47071.html
RelatedPatchThird Party Advisory
Source: cverecord
https://osv.dev/vulnerability/EEF-CVE-2026-47071

SSVC — Action Prioritization

SSVCPoCAutomatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusANALYZED
CWE
CWE-400

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