{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-6776", "assignerOrgId": "f16b083a-5664-49f3-a51e-8d479e5ed7fe", "state": "PUBLISHED", "assignerShortName": "mozilla", "dateReserved": "2026-04-21T12:41:07.296Z", "datePublished": "2026-04-21T12:41:07.745Z", "dateUpdated": "2026-04-21T23:35:11.711Z"}, "containers": {"cna": {"affected": [{"product": "Firefox", "vendor": "Mozilla", "versions": [{"status": "unaffected", "version": "140.10", "lessThanOrEqual": "140.*", "versionType": "rpm"}, {"status": "unaffected", "version": "150", "lessThanOrEqual": "*", "versionType": "rpm"}]}, {"product": "Thunderbird", "vendor": "Mozilla", "versions": [{"status": "unaffected", "version": "140.10", "lessThanOrEqual": "140.*", "versionType": "rpm"}, {"status": "unaffected", "version": "150", "lessThanOrEqual": "*", "versionType": "rpm"}]}], "descriptions": [{"lang": "en", "value": "Incorrect boundary conditions in the WebRTC: Networking component. This vulnerability was fixed in Firefox 150, Firefox ESR 140.10, Thunderbird 150, and Thunderbird 140.10.", "supportingMedia": [{"type": "text/html", "base64": false, "value": "Incorrect boundary conditions in the WebRTC: Networking component. This vulnerability was fixed in Firefox 150, Firefox ESR 140.10, Thunderbird 150, and Thunderbird 140.10."}]}], "title": "Incorrect boundary conditions in the WebRTC: Networking component", "references": [{"url": "https://bugzilla.mozilla.org/show_bug.cgi?id=2021770"}, {"url": "https://www.mozilla.org/security/advisories/mfsa2026-30/"}, {"url": "https://www.mozilla.org/security/advisories/mfsa2026-32/"}, {"url": "https://www.mozilla.org/security/advisories/mfsa2026-33/"}, {"url": "https://www.mozilla.org/security/advisories/mfsa2026-34/"}], "credits": [{"lang": "en", "value": "Nan Wang"}], "providerMetadata": {"orgId": "f16b083a-5664-49f3-a51e-8d479e5ed7fe", "shortName": "mozilla", "dateUpdated": "2026-04-21T23:35:11.711Z"}}, "adp": [{"problemTypes": [{"descriptions": [{"type": "CWE", "cweId": "CWE-119", "lang": "en", "description": "CWE-119 Improper Restriction of Operations within the Bounds of a Memory Buffer"}]}], "metrics": [{"cvssV3_1": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 7.8, "attackVector": "LOCAL", "baseSeverity": "HIGH", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H", "integrityImpact": "HIGH", "userInteraction": "REQUIRED", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "NONE", "confidentialityImpact": "HIGH"}}, {"other": {"type": "ssvc", "content": {"timestamp": "2026-04-21T13:49:53.035013Z", "id": "CVE-2026-6776", "options": [{"Exploitation": "none"}, {"Automatable": "no"}, {"Technical Impact": "total"}], "role": "CISA Coordinator", "version": "2.0.3"}}}], "title": "CISA ADP Vulnrichment", "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-04-21T13:49:59.431Z"}}]}}

{"dataType": "CVE_RECORD", "containers": {"adp": [{"title": "CISA ADP Vulnrichment", "metrics": [{"cvssV3_1": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 7.8, "attackVector": "LOCAL", "baseSeverity": "HIGH", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H", "integrityImpact": "HIGH", "userInteraction": "REQUIRED", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "NONE", "confidentialityImpact": "HIGH"}}, {"other": {"type": "ssvc", "content": {"id": "CVE-2026-6776", "role": "CISA Coordinator", "options": [{"Exploitation": "none"}, {"Automatable": "no"}, {"Technical Impact": "total"}], "version": "2.0.3", "timestamp": "2026-04-21T13:49:53.035013Z"}}}], "problemTypes": [{"descriptions": [{"lang": "en", "type": "CWE", "cweId": "CWE-119", "description": "CWE-119 Improper Restriction of Operations within the Bounds of a Memory Buffer"}]}], "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-04-21T13:49:48.407Z"}}], "cna": {"title": "Incorrect boundary conditions in the WebRTC: Networking component", "credits": [{"lang": "en", "value": "Nan Wang"}], "affected": [{"vendor": "Mozilla", "product": "Firefox", "versions": [{"status": "unaffected", "version": "140.10", "versionType": "rpm", "lessThanOrEqual": "140.*"}, {"status": "unaffected", "version": "150", "versionType": "rpm", "lessThanOrEqual": "*"}]}, {"vendor": "Mozilla", "product": "Thunderbird", "versions": [{"status": "unaffected", "version": "140.10", "versionType": "rpm", "lessThanOrEqual": "140.*"}, {"status": "unaffected", "version": "150", "versionType": "rpm", "lessThanOrEqual": "*"}]}], "references": [{"url": "https://bugzilla.mozilla.org/show_bug.cgi?id=2021770"}, {"url": "https://www.mozilla.org/security/advisories/mfsa2026-30/"}, {"url": "https://www.mozilla.org/security/advisories/mfsa2026-32/"}, {"url": "https://www.mozilla.org/security/advisories/mfsa2026-33/"}, {"url": "https://www.mozilla.org/security/advisories/mfsa2026-34/"}], "descriptions": [{"lang": "en", "value": "Incorrect boundary conditions in the WebRTC: Networking component. This vulnerability was fixed in Firefox 150, Firefox ESR 140.10, Thunderbird 150, and Thunderbird 140.10.", "supportingMedia": [{"type": "text/html", "value": "Incorrect boundary conditions in the WebRTC: Networking component. This vulnerability was fixed in Firefox 150, Firefox ESR 140.10, Thunderbird 150, and Thunderbird 140.10.", "base64": false}]}], "providerMetadata": {"orgId": "f16b083a-5664-49f3-a51e-8d479e5ed7fe", "shortName": "mozilla", "dateUpdated": "2026-04-21T23:35:11.711Z"}}}, "cveMetadata": {"cveId": "CVE-2026-6776", "state": "PUBLISHED", "dateUpdated": "2026-04-21T23:35:11.711Z", "dateReserved": "2026-04-21T12:41:07.296Z", "assignerOrgId": "f16b083a-5664-49f3-a51e-8d479e5ed7fe", "datePublished": "2026-04-21T12:41:07.745Z", "assignerShortName": "mozilla"}, "dataVersion": "5.2"}

{"configurations": [{"nodes": [{"cpeMatch": [{"criteria": "cpe:2.3:a:mozilla:firefox:*:*:*:*:esr:*:*:*", "matchCriteriaId": "15AF037C-5C86-48EB-B1DE-3AC100A34596", "versionEndExcluding": "140.10.0", "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:thunderbird:*:*:*:*:*:*:*:*", "matchCriteriaId": "41C982A2-D35E-4B90-A85E-CD02EDC6DEE9", "versionEndExcluding": "140.10.0", "vulnerable": true}], "negate": false, "operator": "OR"}]}], "cveTags": [], "descriptions": [{"lang": "en", "value": "Incorrect boundary conditions in the WebRTC: Networking component. This vulnerability was fixed in Firefox 150, Firefox ESR 140.10, Thunderbird 150, and Thunderbird 140.10."}], "id": "CVE-2026-6776", "lastModified": "2026-04-22T15:07:55.830", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "LOCAL", "availabilityImpact": "HIGH", "baseScore": 7.8, "baseSeverity": "HIGH", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "REQUIRED", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H", "version": "3.1"}, "exploitabilityScore": 1.8, "impactScore": 5.9, "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "type": "Secondary"}]}, "published": "2026-04-21T13:16:23.350", "references": [{"source": "security@mozilla.org", "tags": ["Permissions Required"], "url": "https://bugzilla.mozilla.org/show_bug.cgi?id=2021770"}, {"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/mfsa2026-32/"}, {"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: Incorrect boundary conditions in the WebRTC: Networking component", "id": "2460110", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2460110"}, "csaw": false, "cvss3": {"cvss3_base_score": "3.4", "cvss3_scoring_vector": "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:L/I:N/A:N", "status": "draft"}, "cwe": "CWE-131", "details": ["A flaw was found in Firefox. The Mozilla Foundation's Security Advisory describes the following issue:\nIncorrect boundary conditions in the WebRTC: Networking component"], "name": "CVE-2026-6776", "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": "2026-04-21T12:41:07Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-6776\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-6776\nhttps://www.mozilla.org/security/advisories/mfsa2026-32/#CVE-2026-6776"], "statement": "Red Hat Product Security rates the severity of this flaw as determined by the Mozilla Foundation Security Advisory.", "threat_severity": "Low"}

{"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": "2026-04-22T13:37:51.815482+00:00", "value": {"mitigation_remediation": ["Upgrade Mozilla Firefox to version 150 or later, or to the ESR 140.10 release, and upgrade Mozilla Thunderbird to version 150 or the ESR 140.10 release, both of which include the fixed WebRTC networking code.", "If an upgrade is not immediately possible, temporarily disable WebRTC by setting media.peerconnection.enabled to false in the about:config settings to prevent peer\u2011to\u2011peer connections from being established.", "Apply network\u2011level controls to block or monitor the ports and protocols typically used by WebRTC, and keep track of any applications that rely on older WebRTC components for potential updates."], "summary": {"action": "Immediate Patch", "impact": "Memory Corruption"}, "threat_synthesis": {"affected_systems": "Mozilla Firefox and Thunderbird browsers are affected when they use the vulnerable WebRTC module. It is inferred that all releases prior to Firefox 150 / ESR 140.10 and Thunderbird 150 / 140.10 remain exposed. Any third\u2011party software that embeds the same WebRTC networking code without the patch is also at risk.", "description_and_impact": "Based on the CVE description, the vulnerability stems from incorrect boundary checking in the WebRTC networking component, which can lead to memory corruption. It is classified as CWE\u2011119 and CWE\u2011131. It is inferred that successful exploitation could potentially compromise the integrity of the browser process.", "risk_and_exploitability": "The CVSS score of 7.8 places the vulnerability in the high\u2011severity range. No EPSS score is available and the issue is not listed in the CISA KEV catalog. It is inferred that the flaw can be triggered by network traffic that reaches the WebRTC component, meaning a malicious web page or remote host could send crafted data to the victim. Successful exploitation would threaten the integrity of the affected process."}}}}, "created": "2026-04-21T17:00:11.950532+00:00", "updated": "2026-04-22T13:45:18.276628+00:00", "vendors": ["mozilla", "mozilla$PRODUCT$firefox"]}