CVE-2026-6767

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{"affected": [{"affectedData": [{"product": "Firefox", "vendor": "Mozilla", "versions": [{"lessThanOrEqual": "115.*", "status": "unaffected", "version": "115.35", "versionType": "rpm"}, {"lessThanOrEqual": "140.*", "status": "unaffected", "version": "140.10", "versionType": "rpm"}, {"lessThanOrEqual": "*", "status": "unaffected", "version": "150", "versionType": "rpm"}]}, {"product": "Thunderbird", "vendor": "Mozilla", "versions": [{"lessThanOrEqual": "140.*", "status": "unaffected", "version": "140.10", "versionType": "rpm"}, {"lessThanOrEqual": "*", "status": "unaffected", "version": "150", "versionType": "rpm"}]}], "source": "security@mozilla.org"}], "configurations": [{"nodes": [{"cpeMatch": [{"criteria": "cpe:2.3:a:mozilla:firefox:*:*:*:*:esr:*:*:*", "matchCriteriaId": "E69D71F5-CAAA-4F28-AB9F-9F898A52D506", "versionEndExcluding": "115.35.0", "vulnerable": true}, {"criteria": "cpe:2.3:a:mozilla:firefox:*:*:*:*:-:*:*:*", "matchCriteriaId": "67B01D49-66FA-4C76-9EB4-2B8CD61FBEB2", "versionEndExcluding": "150.0", "vulnerable": true}, {"criteria": "cpe:2.3:a:mozilla:firefox:*:*:*:*:esr:*:*:*", "matchCriteriaId": "528443E0-C15A-4E70-9187-8E1BAAE84A42", "versionEndExcluding": "140.10.0", "versionStartIncluding": "140.0", "vulnerable": true}, {"criteria": "cpe:2.3:a:mozilla:thunderbird:*:*:*:*:esr:*:*:*", "matchCriteriaId": "6A8A3284-C06C-4591-9548-5324BD91C4FC", "versionEndExcluding": "140.10.0", "versionStartIncluding": "140.0", "vulnerable": true}], "negate": false, "operator": "OR"}]}], "cveTags": [], "descriptions": [{"lang": "en", "value": "Other issue in the Libraries component in NSS. This vulnerability was fixed in Firefox 150, Firefox ESR 115.35, Firefox ESR 140.10, Thunderbird 150, and Thunderbird 140.10."}, {"lang": "es", "value": "Otro problema en el componente de Bibliotecas en NSS. Esta vulnerabilidad fue corregida en Firefox 150, Firefox ESR 115.35, Firefox ESR 140.10, Thunderbird 150, y Thunderbird 140.10."}], "id": "CVE-2026-6767", "lastModified": "2026-10-26T21:10:00.170", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "NONE", "baseScore": 5.3, "baseSeverity": "MEDIUM", "confidentialityImpact": "LOW", "integrityImpact": "NONE", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N", "version": "3.1"}, "exploitabilityScore": 3.9, "impactScore": 1.4, "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "type": "Secondary"}], "ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-6767", "options": [{"exploitation": "none"}, {"automatable": "yes"}, {"technicalImpact": "partial"}], "role": "CISA Coordinator", "timestamp": "2026-05-27T17:09:39.086549Z", "version": "2.0.3"}}]}, "published": "2026-04-21T13:16:22.577", "references": [{"source": "security@mozilla.org", "tags": ["Permissions Required"], "url": "https://bugzilla.mozilla.org/show_bug.cgi?id=2023209"}, {"source": "security@mozilla.org", "tags": ["Vendor Advisory"], "url": "https://www.mozilla.org/security/advisories/mfsa2026-30/"}, {"source": "security@mozilla.org", "tags": ["Vendor Advisory"], "url": "https://www.mozilla.org/security/advisories/mfsa2026-31/"}, {"source": "security@mozilla.org", "tags": ["Vendor Advisory"], "url": "https://www.mozilla.org/security/advisories/mfsa2026-32/"}, {"source": "security@mozilla.org", "tags": ["Vendor Advisory"], "url": "https://www.mozilla.org/security/advisories/mfsa2026-33/"}, {"source": "security@mozilla.org", "tags": ["Vendor Advisory"], "url": "https://www.mozilla.org/security/advisories/mfsa2026-34/"}], "sourceIdentifier": "security@mozilla.org", "vulnStatus": "Analyzed", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-119"}], "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "type": "Secondary"}]}

{"bugzilla": {"description": "firefox: Other issue in the Libraries component in NSS", "id": "2460086", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2460086"}, "csaw": false, "cvss3": {"cvss3_base_score": "6.1", "cvss3_scoring_vector": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N", "status": "draft"}, "cwe": "CWE-676", "details": ["A flaw was found in Firefox. The Mozilla Foundation's Security Advisory describes the following issue:\nOther issue in the Libraries component in NSS"], "name": "CVE-2026-6767", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Not affected", "package_name": "firefox", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Not affected", "package_name": "rhel10/firefox-flatpak", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:6", "fix_state": "Not affected", "package_name": "firefox", "product_name": "Red Hat Enterprise Linux 6"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "firefox", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Not affected", "package_name": "firefox", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Not affected", "package_name": "firefox", "product_name": "Red Hat Enterprise Linux 9"}], "public_date": "2026-04-21T12:41:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-6767\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-6767\nhttps://www.mozilla.org/security/advisories/mfsa2026-31/#CVE-2026-6767\nhttps://www.mozilla.org/security/advisories/mfsa2026-32/#CVE-2026-6767"], "statement": "Red Hat Product Security rates the severity of this flaw as determined by the Mozilla Foundation Security Advisory.", "threat_severity": "Moderate"}

{"affected": [{"configurations": [{"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[115.35,116.0.0)"}}, {"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": "2026-04-22T15:10:09.615279+00:00", "value": {"mitigation_remediation": ["Upgrade Firefox to version 150 or to one of the ESR releases 115.35 or 140.10 that contain the fix.", "Upgrade Thunderbird to version 150 or to one of the ESR releases 115.35 or 140.10 that contain the fix.", "Deploy the updated software across all impacted systems to ensure the vulnerability is eliminated.", "Continue to monitor Mozilla security advisories for any changes to the advisory or additional patches."], "summary": {"action": "Patch Software", "impact": "Buffer overflow (memory corruption)"}, "threat_synthesis": {"affected_systems": "Mozilla Firefox and Thunderbird are affected. All releases prior to Firefox 150, ESR 115.35, and ESR 140.10, as well as all releases prior to Thunderbird 150 and 140.10 contain the vulnerability. The fixes were applied in the specified newer versions, so only earlier builds are vulnerable.", "description_and_impact": "The CVE describes a buffer overflow in the NSS libraries, identified as CWE\u2011119 and CWE\u2011676. This flaw can corrupt memory and potentially allow an attacker to execute arbitrary code or cause other unintended behavior. The CVSS score of 5.3 classifies the risk as moderate.", "risk_and_exploitability": "The CVSS score indicates a moderate severity, yet the EPSS score is not available and the vulnerability is not listed in the CISA KEV catalog. The attack vector is not explicitly described, but given the nature of the flaw it could be leveraged by an attacker through an NSS library exploit, potentially remotely if the library is used in network services. Overall, the risk level remains uncertain but should be considered moderate pending further information."}}}}, "created": "2026-04-21T17:00:11.950937+00:00", "title": "Buffer Overflow in NSS Libraries of Firefox and Thunderbird", "updated": "2026-04-22T15:15:16.423168+00:00", "vendors": ["mozilla", "mozilla$PRODUCT$firefox"]}