CVE-2026-47071
HighPublic exploitSOCKS5 TLS upgrade ignores caller timeout in hackney
Published May 25, 2026 · Updated Oct 8, 2026 · Also known as EEF-CVE-2026-47071, EUVD-2026-31685, GHSA-gp9c-pm5m-5cxr
Key Facts
Patch immediately- CVE-2026-47071 is a high-severity vulnerability (CVSS 8.2 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 4.0.1, Hackney 5ccdab725c561a6f03d05a51f2d0664f98236dae.
- Brandefense priority: patch immediately, because public exploit code exists for a high-severity flaw.
CVSS v4
8.2
CVSS:4.0/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
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-2026-47071 brief as a PDF
Every affected product and fixed release, exploitation status and a first 24 hours response checklist, emailed within minutes.
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 Products
3 affected entries in total| Product | Affected versions | Fixed in |
|---|---|---|
| HackneyBenoitc | >= 0.10.0 | 4.0.1 |
Patched Releases
Hackney
4.0.1, 5ccdab725c561a6f03d05a51f2d0664f98236dae
Timeline
Publicly disclosed
May 25, 2026
Last updated
Oct 8, 2026
Weakness Type
- CWE-400 Uncontrolled Resource Consumption
References
- advisoryGHSA advisory
- advisoryhttps://github.com/benoitc/hackney/security/advisories/GHSA-gp9c-pm5m-5cxr
- advisoryhttps://github.com/CVEProject/cvelistV5/tree/main/cves/2026/47xxx/CVE-2026-47071.json
- advisoryhttps://nvd.nist.gov/vuln/detail/CVE-2026-47071
- patchhttps://github.com/benoitc/hackney/commit/5ccdab725c561a6f03d05a51f2d0664f98236dae
FAQ
Common Questions.
Uncontrolled Resource Consumption vulnerability in benoitc hackney allows Flooding.
Affected: Hackney (Benoitc) versions >= 0.10.0. 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 4.0.1, Hackney 5ccdab725c561a6f03d05a51f2d0664f98236dae.
Brandefense priority: patch immediately, because public exploit code exists for a high-severity flaw.
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