CVE-2026-48861
Published:June 02, 2026
Updated:June 07, 2026
Improper Neutralization of CRLF Sequences ('CRLF Injection') vulnerability in elixir-mint Mint allows HTTP Request Splitting and HTTP Request Smuggling.
In lib/mint/http1/request.ex, the encode_request_line/2 function splices the caller-supplied method and target arguments directly into the HTTP/1 request line without any character validation: [method, ?\s, target, " HTTP/1.1\r\n"]. An application that forwards attacker-controlled input as the HTTP method or target to Mint.HTTP.request/5 is therefore exposed to request-line CRLF injection: the attacker can terminate the request line early, inject arbitrary headers, and smuggle an entirely separate pipelined HTTP request onto the same TCP connection.
Mint 1.7.0 introduced validate_request_target/2, which rejects CRLF and other control characters in the target by default and closes the path/query vector unless the caller opts out via skip_target_validation: true. The method field remains unvalidated, so the method-based injection is exploitable under the default Mint configuration on all versions.
This issue affects mint: from 0.1.0 before 1.9.0.
Affected Packages
https://github.com/elixir-mint/mint.git (GITHUB):
Affected version(s) >=v0.1.0 <v1.9.0Fix Suggestion:
Update to version v1.9.0mint (HEX):
Affected version(s) >=0.1.0 <1.9.0Fix Suggestion:
Update to version 1.9.0Related Resources (5)
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Contact UsCVSS v4
Base Score:
2.1
Attack Vector
LOCAL
Attack Complexity
LOW
Attack Requirements
PRESENT
Privileges Required
NONE
User Interaction
NONE
Vulnerable System Confidentiality
NONE
Vulnerable System Integrity
LOW
Vulnerable System Availability
NONE
Subsequent System Confidentiality
NONE
Subsequent System Integrity
LOW
Subsequent System Availability
NONE
CVSS v3
Base Score:
4.3
Attack Vector
LOCAL
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
CHANGED
Confidentiality
NONE
Integrity
LOW
Availability
NONE
Weakness Type (CWE)
Improper Neutralization of CRLF Sequences ('CRLF Injection')
EPSS
Base Score:
0.02