CVE-2026-87859

A flaw was found in morgan, an HTTP request logger middleware for Node.js. An unauthenticated remote attacker can exploit this vulnerability by injecting an unescaped double quote into a log field they control, such as the User-Agent or Referer header. This causes the log field to close...

CVE-2026-87859

morgan is an HTTP request logger middleware for Node.js. In versions before 1.12.1 , the escapeLogField() function fails to escape the double quote character, which delimits quoted fields in the Apache combined log format. An unauthenticated remote attacker who controls a value written to a quote...

CVE-2026-87859 morgan vulnerable to Log Injection via unescaped double quote in quoted log fields

morgan is an HTTP request logger middleware for Node.js. In versions before 1.12.1, its escapeLogField function does not escape the double quote character, which delimits the quoted fields of the Apache combined log format that morgan emits. An unauthenticated remote attacker who controls a value...