Description
lettersanitizer is a DOM-based HTML email sanitizer for in-browser email rendering. All versions of lettersanitizer below 1.0.2 are affected by a denial of service issue when processing a CSS at-rule `@keyframes`. This package is depended on by [react-letter](https://github.com/mat-sz/react-letter), therefore everyone using react-letter is also at risk. The problem has been patched in version 1.0.2.
Remediation
References
https://github.com/mat-sz/react-letter/issues/17
https://github.com/mat-sz/lettersanitizer/security/advisories/GHSA-7r3r-gq8p-v9jj
https://github.com/mat-sz/lettersanitizer/commit/96d3dfe2ef0465d47324ed4d13e91ba0816a173f