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{"bugzilla": {"description": "firefox: thunderbird: Memory safety bugs fixed in Firefox ESR 140.10, Thunderbird ESR 140.10, Firefox 150 and Thunderbird 150", "id": "2460088", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2460088"}, "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"}, "cwe": "CWE-787", "details": ["A flaw was found in Firefox and Thunderbird. The Mozilla Foundation's Security Advisory describes the following issue:\nMemory safety bugs present in Firefox ESR 140.9, Thunderbird ESR 140.9, Firefox 149 and Thunderbird 149. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code."], "name": "CVE-2026-6786", "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": "2026-04-21T12:41:14Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-6786\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-6786\nhttps://www.mozilla.org/security/advisories/mfsa2026-32/#CVE-2026-6786"], "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": "unaffected", "versions": {"scheme": "generic", "value": "[140.10,141.0.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[150,*]"}}], "enrichment": {"confidence": 100.0, "confidence_source": "matching", "scores": [{"score": 100.0, "source": "matching"}]}, "original": {"product": "Firefox", "source": "cna", "vendor": "Mozilla"}, "product": "firefox", "vendor": "mozilla"}], "analysis": {"en": {"generated_at": "2026-04-22T05:40:49.965348+00:00", "value": {"mitigation_remediation": ["Install the latest Firefox ESR 140.10 or Firefox 150 update on all relevant systems.", "Uninstall or disable legacy extensions that may trigger the affected code paths until the update is applied.", "Apply enterprise browser policy to block execution of unsigned add-ons and restrict access to unmanaged content domains pending the update."], "summary": {"action": "Immediate Patch", "impact": "Remote Code Execution"}, "threat_synthesis": {"affected_systems": "Mozilla Firefox and Thunderbird are affected when running ESR 140.9, Thunderbird ESR 140.9, Firefox 149, or Thunderbird 149. The fix is available in Firefox 150, Thunderbird 150, and the ESR 140.10 releases.", "description_and_impact": "Memory safety bugs were identified in older releases of Firefox and Thunderbird that could corrupt memory. The impact is the potential to execute arbitrary code on the affected system, as indicated by the possibility of memory corruption leading to remote code execution. The vulnerabilities are mapped to common weaknesses involving buffer overflows and use\u2011after\u2011free errors, allowing an attacker to gain code execution rights.", "risk_and_exploitability": "The CVSS score of 8.1 reflects high severity, and although there is no EPSS data, the absence from CISA\u2019s KEV catalog suggests it has not yet been widely exploited. Based on the description, the likely attack vector is through maliciously crafted web content or locally installed data that triggers the memory corruption. The risk is significant for systems that still run the vulnerable versions with unrestricted web or local file access."}}}}, "created": "2026-04-21T16:30:40.489777+00:00", "updated": "2026-04-22T05:45:09.827486+00:00", "vendors": ["mozilla", "mozilla$PRODUCT$firefox"]}