CVE-2026-47075: hackney — Exploit & Fix

Description

Improper Neutralization of CRLF Sequences vulnerability in benoitc hackney allows HTTP Request Splitting. hackney does not percent-encode carriage return (\r) or line feed (\n) characters in the URL query component before constructing the HTTP/1.1 request target. Characters outside the grammar defined in RFC 3986 Section 3.4 must be percent-encoded, but hackney_url:make_url/3 passes the query binary directly without validation or escaping. An attacker who can control all or part of a URL passed to hackney can inject raw CRLF sequences into the query string, which are then sent as HTTP line breaks in the request target. This enables injection of arbitrary HTTP headers or splitting of the HTTP request. This issue affects hackney: from 0 before 4.0.1.

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CVSS v3.1 Score

7.5

HIGH

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

EPSS — Exploit Prediction

0.0039

Probability of exploitation

0.31%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-93 CWE-93

Affected Products

Vendor	Product	Versions
benoitc	hackney	< 4.0.1

References

Advisories & Patches

https://cna.erlef.org/cves/CVE-2026-47075.html https://github.com/benoitc/hackney/commit/ca73dd0aba0ed557449c18288bf07241671a43c9 https://github.com/benoitc/hackney/security/advisories/GHSA-j9wq-vxxc-94wf https://osv.dev/vulnerability/EEF-CVE-2026-47075 https://github.com/benoitc/hackney/security/advisories/GHSA-j9wq-vxxc-94wf

Exploits

https://github.com/benoitc/hackney/security/advisories/GHSA-j9wq-vxxc-94wf https://github.com/benoitc/hackney/security/advisories/GHSA-j9wq-vxxc-94wf

Frequently Asked Questions

What is CVE-2026-47075? +

Improper Neutralization of CRLF Sequences vulnerability in benoitc hackney allows HTTP Request Splitting. hackney does not percent-encode carriage return (\r) or line feed (\n) characters in the URL query component before constructing the HTTP/1.1 request target. Characters outside the grammar defined in RFC 3986 Section 3.4 must be percent-encoded, but hackney_url:make_url/3 passes the query binary directly without validation or escaping. An attacker who can control all or part of a URL passed to hackney can inject raw CRLF sequences into the query string, which are then sent as HTTP line breaks in the request target. This enables injection of arbitrary HTTP headers or splitting of the HTTP request. This issue affects hackney: from 0 before 4.0.1. It has a CVSS v3.1 base score of 7.5 (HIGH).

How severe is CVE-2026-47075? +

CVE-2026-47075 has a CVSS v3.1 score of 7.5 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching. The EPSS score is 0.0039, placing it in the 0th percentile for exploitation probability.

What products are affected by CVE-2026-47075? +

CVE-2026-47075 affects products from benoitc, specifically: hackney. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2026-47075? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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