LiquidJS is a Shopify / GitHub Pages compatible template engine in pure JavaScript. Prior to version 10.25.1, the `replace_first` filter in LiquidJS uses JavaScript's `String.prototype.replace()` which interprets `$&` as a back reference to the matched substring. The filter only charges `memoryLimit` for the input string length, not the amplified output. An attacker can achieve exponential memory amplification (up to 625,000:1) while staying within the `memoryLimit` budget, leading to denial of service. Version 10.25.1 patches the issue.
https://github.com/harttle/liquidjs/security/advisories/GHSA-6q5m-63h6-5x4v
https://github.com/harttle/liquidjs/commit/35d523026345d80458df24c72e653db78b5d061d