CVE-2026-6781

Description

Denial-of-service in the Audio/Video: Playback component. This vulnerability was fixed in Firefox 150 and Thunderbird 150.

CVSS Details

CVSS Score

7.5

Severity

HIGH

CVSS Vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Configurations (Affected Products)

cpe:2.3:a:mozilla:firefox:*:*:*:*:-:*:*:* - VULNERABLE

cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:* - VULNERABLE

Firefox < 150

Thunderbird < 150

PoC / Exploit Code

⚠ For Security Research Only

The following code is for security research and authorized testing only.

python

<!--
PoC for CVE-2026-6781
Description: Conceptual PoC demonstrating the trigger vector.
Note: Requires a specifically malformed media file to exploit the A/V playback component.
-->
<!DOCTYPE html>
<html>
<head>
    <title>CVE-2026-6781 PoC</title>
</head>
<body>
    <h1>CVE-2026-6781 DoS Test</h1>
    <!-- Embed the malicious audio/video file -->
    <video id="exploitVideo" autoplay loop>
        <source src="malicious_payload.mp4" type="video/mp4">
    </video>

    <script>
        // Script to ensure playback starts automatically
        document.addEventListener('DOMContentLoaded', function() {
            var video = document.getElementById('exploitVideo');
            video.play().catch(function(error) {
                console.log('Autoplay failed, interaction might be required: ' + error);
            });
        });
    </script>
</body>
</html>

References

[1] CVE.org https://www.cve.org/CVERecord?id=CVE-2026-6781
[2] NVD NIST https://nvd.nist.gov/vuln/detail/CVE-2026-6781
[3] CVE Details https://www.cvedetails.com/cve/CVE-2026-6781/
[4] VulDB https://vuldb.com/cve/CVE-2026-6781
[5] https://bugzilla.mozilla.org/show_bug.cgi?id=2025583
[6] https://www.mozilla.org/security/advisories/mfsa2026-30/
[7] https://www.mozilla.org/security/advisories/mfsa2026-33/

Raw JSON Data

JSON

{"cve": {"id": "CVE-2026-6781", "sourceIdentifier": "[email protected]", "published": "2026-04-21T13:16:23.770", "lastModified": "2026-04-22T15:09:13.913", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "Denial-of-service in the Audio/Video: Playback component. This vulnerability was fixed in Firefox 150 and Thunderbird 150."}], "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": "150.0", "matchCriteriaId": "67B01D49-66FA-4C76-9EB4-2B8CD61FBEB2"}, {"vulnerable": true, "criteria": "cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:*", "versionEndExcluding": "150.0", "matchCriteriaId": "4C81F2D4-C004-4354-B3E2-E3F407DAB22A"}]}]}], "references": [{"url": "https://bugzilla.mozilla.org/show_bug.cgi?id=2025583", "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/mfsa2026-33/", "source": "[email protected]", "tags": ["Vendor Advisory"]}]}}