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{"bugzilla": {"description": "firefox: Use-after-free in the JavaScript Engine component", "id": "2442316", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2442316"}, "csaw": false, "cvss3": {"cvss3_base_score": "7.5", "cvss3_scoring_vector": "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H", "status": "draft"}, "details": ["No description is available for this CVE."], "name": "CVE-2026-2763", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Affected", "package_name": "firefox", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Affected", "package_name": "rhel10/firefox-flatpak", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:6", "fix_state": "Out of support scope", "package_name": "firefox", "product_name": "Red Hat Enterprise Linux 6"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Affected", "package_name": "firefox", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Affected", "package_name": "firefox", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Affected", "package_name": "firefox", "product_name": "Red Hat Enterprise Linux 9"}], "public_date": "2026-02-24T13:33:02Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-2763\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-2763\nhttps://www.mozilla.org/security/advisories/mfsa2026-15/#CVE-2026-2763"], "statement": "Red Hat Product Security rates the severity of this flaw as determined by the Mozilla Foundation Security Advisory.", "threat_severity": "Important"}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "generic", "value": "[0,148)"}}], "enrichment": {"confidence": 100.0, "confidence_source": "matching", "scores": [{"score": 100.0, "source": "matching"}]}, "original": {"product": "Firefox", "source": "cna", "vendor": "Mozilla"}, "product": "firefox", "vendor": "mozilla"}, {"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "generic", "value": "[0,115.33)"}}], "enrichment": {"confidence": 100.0, "confidence_source": "matching", "scores": [{"score": 100.0, "source": "matching"}]}, "original": {"product": "Firefox ESR", "source": "cna", "vendor": "Mozilla"}, "product": "firefox_esr", "vendor": "mozilla"}, {"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "generic", "value": "[0,140.8)"}}], "enrichment": {"confidence": 100.0, "confidence_source": "matching", "scores": [{"score": 100.0, "source": "matching"}]}, "original": {"product": "Firefox ESR", "source": "cna", "vendor": "Mozilla"}, "product": "firefox_esr", "vendor": "mozilla"}, {"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "generic", "value": "[0,148)"}}], "enrichment": {"confidence": 100.0, "confidence_source": "matching", "scores": [{"score": 100.0, "source": "matching"}]}, "original": {"product": "Thunderbird", "source": "cna", "vendor": "Mozilla"}, "product": "thunderbird", "vendor": "mozilla"}, {"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "generic", "value": "[0,140.8)"}}], "enrichment": {"confidence": 100.0, "confidence_source": "matching", "scores": [{"score": 100.0, "source": "matching"}]}, "original": {"product": "Thunderbird", "source": "cna", "vendor": "Mozilla"}, "product": "thunderbird", "vendor": "mozilla"}], "analysis": {"en": {"generated_at": "2026-04-15T15:44:56.975488+00:00", "value": {"mitigation_remediation": ["Update Firefox to version 148 or newer, including ESR 115.33 or ESR 140.8, which contain the JavaScript engine fix.", "Update Thunderbird to version 148 or newer, including ESR 140.8, to apply the corresponding patch.", "If an upgrade cannot be performed immediately, mitigate risk by restricting or disabling JavaScript execution for untrusted web content or using a sandboxed browsing environment for email and web access."], "summary": {"action": "Immediate Patch", "impact": "Remote Code Execution"}, "threat_synthesis": {"affected_systems": "Mozilla Firefox and Thunderbird, including the standard, Extended Support Release (ESR) branches. The security patches are delivered in Firefox v148, ESR 115.33 and ESR 140.8, and in Thunderbird v148 and ESR 140.8; any older versions of these browsers are potentially affected.", "description_and_impact": "A use\u2011after\u2011free flaw in the JavaScript engine can allow an attacker to execute arbitrary code while a vulnerable program is running. The vulnerability in the JavaScript object model can be triggered by malformed or malicious script that releases a memory object before it is fully cleaned up, leading to a crash or arbitrary code execution. The flaw falls under CWE\u2011416, which indicates that the program can access memory after it has been freed.", "risk_and_exploitability": "The CVSS base score is 9.8, denoting critical severity, but the EPSS score is under 1\u202f%, indicating a low probability of exploitation in the wild. The vulnerability is not listed in the CISA KEV catalog. The likely attack path involves delivering malicious JavaScript through web content or email, which the affected browser will execute, giving the attacker foothold in the user\u2019s environment. The lack of a public exploit makes the threat largely theoretical but the severity warrants immediate action."}}}}, "created": "2026-02-25T11:39:43.751037+00:00", "updated": "2026-04-15T17:15:10.586815+00:00", "vendors": ["mozilla", "mozilla$PRODUCT$firefox", "mozilla$PRODUCT$firefox_esr", "mozilla$PRODUCT$thunderbird"]}