CVE-2026-33287

LiquidJS has Exponential Memory Amplification through its replace_first Filter $& Pattern

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.

Affected

harttle · liquidjs

CVSS v3.1 GITHUB

7.5 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS

0.52% chance of exploitation in the next 30 days, 43rd percentile

Published

2026-03-26

Proof-of-concept exploits (1)

• advisories/GHSA-6q5m-63h6-5x4v

Security advisories

• harttle/liquidjs/security/advisories/GHSA-6q5m-63h6-5x4v
• harttle/liquidjs/commit/35d523026345d80458df24c72e653db78b5d061d

References

• CVE Record
• NVD entry