Warning about bidirectional Unicode text

A warning is now displayed when a file's contents include bidirectional Unicode text. Such text can be interpreted or compiled differently than it appears in a user interface. For example, hidden, bidirectional Unicode characters can be used to swap segments of text in a file. This can cause code to appear one way and be interpreted or compiled another way.


This security issue is the topic of the Common Vulnerabilities and Exposures (CVE) publication: CVE-2021-42574. If your use of bidirectional Unicode characters is intentional and not malformed, you can ignore the warning.

To review a file for which this warning is displayed, open it in an editor that will display the hidden, bidirectional Unicode characters, like Visual Studio Code which highlights the characters by default. Then, verify that the characters are necessary and not disguising text that will be interpreted or compiled differently than it appears.

For more information, refer to Trojan Source: Invisible Source Code Vulnerabilities.