PHP_CodeSniffer tokenizes PHP files and detects violations of a defined set of coding standards. Prior to versions 3.13.6 and 4.0.2, PHP_CodeSniffer contains a command injection vulnerability in the code that generates the Gitblame, Hgblame, and Svnblame report formats. As a result, running PHP_CodeSniffer over untrusted files, for example in a continuous integration pipeline that scans pull requests, or on a developer machine reviewing third party code, could result in attacker controlled shell commands being executed when the Gitblame, Hgblame, or Svnblame report processes a file whose name contains shell metacharacters. Users using the default Full report, or any of the other non-blame reports, are not affected. Users on a runtime platform which does not allow filenames to contain shell metacharacters, such as " and ;, are not affected. This issue is fixed in versions 3.13.6 and 4.0.2.