CVE-2026-6758

Use-after-free in the JavaScript: WebAssembly component. This vulnerability was fixed in Firefox 150 and Thunderbird 150.

CVSS v3 7.5 HIGH

7.5^/10

CVSS v3 : HIGH

Vector :

Exploitability : 3.9 / Impact : 3.6

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact NONE

Availability Impact HIGH

Scope UNCHANGED

References

Link	Resource
https://bugzilla.mozilla.org/show_bug.cgi?id=2013619	Permissions Required
https://www.mozilla.org/security/advisories/mfsa2026-30/	Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2026-33/	Vendor Advisory

Configurations

Configuration 1 (hide)

OR	cpe:2.3:a:mozilla:firefox:::::-:::*
	cpe:2.3:a:mozilla:thunderbird::::::::

History

26 Oct 2026, 22:10

Type	Values Removed	Values Added
Summary		(es) Uso después de liberación en el componente javascript_disabled: WebAssembly. Esta vulnerabilidad se corrigió en Firefox 150 y Thunderbird 150.

Information

Published : 2026-04-21 13:16

Updated : 2026-10-26 22:10

NVD link : CVE-2026-6758

Mitre link : CVE-2026-6758

CVE.ORG link : CVE-2026-6758

JSON object : View

Products Affected

mozilla

firefox
thunderbird

CWE

CWE-416

Use After Free

{"id": "CVE-2026-6758", "cveTags": [], "metrics": {"ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-6758", "role": "CISA Coordinator", "options": [{"exploitation": "none"}, {"automatable": "yes"}, {"technicalImpact": "partial"}], "version": "2.0.3", "timestamp": "2026-04-22T15:06:30.502426Z"}}], "cvssMetricV31": [{"type": "Secondary", "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 7.5, "attackVector": "NETWORK", "baseSeverity": "HIGH", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "integrityImpact": "NONE", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "NONE", "confidentialityImpact": "NONE"}, "impactScore": 3.6, "exploitabilityScore": 3.9}]}, "affected": [{"source": "security@mozilla.org", "affectedData": [{"vendor": "Mozilla", "product": "Firefox", "versions": [{"status": "unaffected", "version": "150", "versionType": "rpm", "lessThanOrEqual": "*"}]}, {"vendor": "Mozilla", "product": "Thunderbird", "versions": [{"status": "unaffected", "version": "150", "versionType": "rpm", "lessThanOrEqual": "*"}]}]}], "published": "2026-04-21T13:16:21.770", "references": [{"url": "https://bugzilla.mozilla.org/show_bug.cgi?id=2013619", "tags": ["Permissions Required"], "source": "security@mozilla.org"}, {"url": "https://www.mozilla.org/security/advisories/mfsa2026-30/", "tags": ["Vendor Advisory"], "source": "security@mozilla.org"}, {"url": "https://www.mozilla.org/security/advisories/mfsa2026-33/", "tags": ["Vendor Advisory"], "source": "security@mozilla.org"}], "vulnStatus": "Analyzed", "weaknesses": [{"type": "Secondary", "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "description": [{"lang": "en", "value": "CWE-416"}]}], "descriptions": [{"lang": "en", "value": "Use-after-free in the JavaScript: WebAssembly component. This vulnerability was fixed in Firefox 150 and Thunderbird 150."}, {"lang": "es", "value": "Uso despu\u00e9s de liberaci\u00f3n en el componente javascript_disabled: WebAssembly. Esta vulnerabilidad se corrigi\u00f3 en Firefox 150 y Thunderbird 150."}], "lastModified": "2026-10-26T22:10:00.163", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:a:mozilla:firefox:*:*:*:*:-:*:*:*", "vulnerable": true, "matchCriteriaId": "67B01D49-66FA-4C76-9EB4-2B8CD61FBEB2", "versionEndExcluding": "150.0"}, {"criteria": "cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "4C81F2D4-C004-4354-B3E2-E3F407DAB22A", "versionEndExcluding": "150.0"}], "operator": "OR"}]}], "sourceIdentifier": "security@mozilla.org"}