CVE-2026-45617CWE-1333

LiquidJS: ReDoS via Quadratic Backtracking in `strip_html` Filter Regex

High · published June 17, 2026

CVSS v3.1
7.5
EPSS
1%
Percentile
50.8
In the wild
Unconfirmed
What it is

LiquidJS is a Shopify/GitHub Pages compatible template engine written in pure JavaScript. In versions 10.25.7 and below, the built-in strip_html filter uses a regex containing four flawed lazy-quantified alternatives, leading to ReDoS via quadratic backtracking. When the input contains many <script, <style, or <!-- opener tokens without matching closers, the V8 regex engine performs O(N²) backtracking, blocking the Node.js event loop. A single ~350 KB request ('<script'.repeat(50000)) stalls the process for ~10 seconds; cost grows quadratically with input size. The default memoryLimit: Infinity does not bound regex CPU, and even when configured strip_html only charges str.length to the limit — the regex itself runs unbounded. A single unauthenticated request containing crafted untrusted input can cause severe event-loop blocking and CPU amplification that saturates Node.js workers while bypassing memoryLimit protections. This issue has been fixed in version 10.26.0.

The record
Technical detail
CVSS v3.1
7.5 · HIGH
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CVSS v4.0
Not supplied
EPSS
0.00655 · 50.8th percentile
Weakness
CWE-1333 · Inefficient Regular Expression Complexity
Published
2026-06-17T22:14Z
EPSS history
Timeline
  • 17 JUN 22:14Z
    LiquidJS: ReDoS via Quadratic Backtracking in `strip_html` Filter Regex
    cvelistv5