SB2026010581 - CRLF injection in cpp-httplib

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Main Vulnerability Database SB2026010581

SB2026010581 - CRLF injection in cpp-httplib

Published: January 5, 2026

Security Bulletin ID SB2026010581
CSH Severity
Medium
Patch available
YES
Number of vulnerabilities 1
Exploitation vector Remote access
Highest impact Data manipulation

Breakdown by Severity

Medium 100%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 1 vulnerability.


1) CRLF injection (CVE-ID: CVE-2026-21428)

CWE-ID: CWE-93 - Improper Neutralization of CRLF Sequences ('CRLF Injection')

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N/E:U/U:Green


The vulnerability allows a remote attacker to inject arbitrary HTTP headers.

The vulnerability exists due to insufficient validation of attacker-supplied data. A remote attacker can send a specially crafted HTTP request to the application containing CR-LF characters and modify application behavior. When combined with a server that supports http1.1 pipelining this can be used for server side request forgery attacks.


Remediation

Install update from vendor's website.

References