CVE-2026-47075

MEDIUMCVSS 6.8/10EPSS 0.42%

Last modified

CVE-2026-47075 is a medium-severity vulnerability rated 6.8/10 on the CVSS scale. 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. EPSS estimates a 0.42% chance of exploitation in the next 30 days.

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.

Metrics

CVSS 3.1
7.5/10

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

CVSS 4.0
6.8/10

CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:A/VC:N/VI:H/VA:N/SC:N/SI:H/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 Probability
0.42%

33.8th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

VendorProductVersions
BenoitcHackney< 4.0.1

References

Timeline

Published
Last Modified
Status
Analyzed

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.
How severe is CVE-2026-47075?
CVE-2026-47075 has a CVSS score of 6.8/10 (MEDIUM severity). The EPSS model estimates a 0.42% probability of exploitation in the next 30 days.
How do I fix CVE-2026-47075?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2026-47075?

Run a free Strix scan to check your systems for this vulnerability.

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Source: NVD / NIST