CVE-2026-47072: benoitc hackney · CRLF Injection
Affects benoitc hackneySource CVE Database V5
Not known to be exploited · CVSS 6.9 Medium : upgrade to 4.0.1 when convenient.
Data as of 26 Oct 2026, 06:26 UTC
- EPSS
- 0.5% chance of exploitation in 30 days – higher than 45% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 4.0.1, 52310ca807e7b48441ba0e9129171f535313fdd1
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:H/SA:NExploitation evidence
Disclosed: evidence found.
CVE published 25 May 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 2026-10-26.
What to do
Upgrade hackney to 4.0.1; hackney to 52310ca807e7b48441ba0e9129171f535313fdd1.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| benoitchackney | Affected
| Fixed in
|
| benoitchackney | Affected
| Fixed in
|
Hexhackneypkg:hex/hackneyOther threats | Affected
| Fixed in– |
Hexhackneypkg:hex/hackneyOther threats | Affected
| Fixed in
|
GitHubbenoitc/hackneypkg:github/benoitc/hackneyOther threats | Affected– | Fixed in– |
CPE configurations (1)
cpe:2.3:a:benoitc:hackney:*:*:*:*:*:*:*:*
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
Input validation or sanitization to remove CRLF and NUL characters before passing these options is recommended as a temporary mitigation until an official fix is released.
Description
Improper Neutralization of CRLF Sequences ('CRLF Injection') vulnerability in benoitc hackney allows HTTP Request/Response Splitting. The WebSocket upgrade code in src/hackney_ws.erl copies the host, path, headers (ExtraHeaders), and protocols options from the caller-supplied opts map into the internal #ws_data{} record in init/1 and then splices them verbatim into the raw HTTP/1.1 upgrade request by binary concatenation in do_handshake/1. No CRLF or NUL stripping is performed at any of these four injection sites. An attacker who controls any of these options — for example by forwarding URL components or header values from untrusted input into hackney_ws:start_link/1 — can inject arbitrary HTTP headers into the outbound WebSocket upgrade request, leading to header injection, credential spoofing toward the upstream server, log and cache poisoning, or request smuggling via intermediary proxies. This issue affects hackney: from 2.0.0 before 4.0.1.
References
- github.com/benoitc/hackney/security/advisories/GHSA-f9vr-g2g2-x9fg (opens in a new tab)
- cna.erlef.org/cves/CVE-2026-47072.html (opens in a new tab)
- osv.dev/vulnerability/EEF-CVE-2026-47072 (opens in a new tab)
- github.com/benoitc/hackney/commit/52310ca807e7b48441ba0e9129171f535313fdd1 (opens in a new tab)