CVE-2026-56846

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-56846", "assignerOrgId": "36234546-b8fa-4601-9d6f-f4e334aa8ea1", "state": "PUBLISHED", "assignerShortName": "hackerone", "dateReserved": "2026-06-23T15:00:03.632Z", "datePublished": "2026-08-04T00:49:58.319Z", "dateUpdated": "2026-08-04T15:03:38.709Z"}, "containers": {"cna": {"descriptions": [{"lang": "en", "value": "A flaw in Node.js HTTP/2 handling can cause HTTP/2 retained header blocks evade maxSessionMemory and enable remote memory exhaustion.\r\n\r\nThis vulnerability affects Node.js **24.x** and **22.x**."}], "affected": [{"defaultStatus": "unaffected", "vendor": "nodejs", "product": "node", "versions": [{"version": "24.18.0", "status": "affected", "lessThanOrEqual": "24.18.0", "versionType": "semver"}, {"version": "22.23.1", "status": "affected", "lessThanOrEqual": "22.23.1", "versionType": "semver"}]}], "references": [{"url": "https://nodejs.org/en/blog/vulnerability/july-2026-security-releases"}], "metrics": [{"cvssV3_0": {"version": "3.0", "vectorString": "CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "baseScore": 7.5, "baseSeverity": "HIGH"}}], "problemTypes": [{"descriptions": [{"type": "CWE", "lang": "en", "cweId": "CWE-400", "description": "CWE-400 Uncontrolled Resource Consumption"}]}], "providerMetadata": {"orgId": "36234546-b8fa-4601-9d6f-f4e334aa8ea1", "shortName": "hackerone", "dateUpdated": "2026-08-04T00:49:58.319Z"}}, "adp": [{"metrics": [{"other": {"type": "ssvc", "content": {"timestamp": "2026-08-04T14:28:25.511403Z", "id": "CVE-2026-56846", "options": [{"Exploitation": "none"}, {"Automatable": "yes"}, {"Technical Impact": "partial"}], "role": "CISA Coordinator", "version": "2.0.3"}}}], "title": "CISA ADP Vulnrichment", "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-08-04T15:03:38.709Z"}}]}}

{"dataType": "CVE_RECORD", "containers": {"adp": [{"title": "CISA ADP Vulnrichment", "metrics": [{"other": {"type": "ssvc", "content": {"id": "CVE-2026-56846", "role": "CISA Coordinator", "options": [{"Exploitation": "none"}, {"Automatable": "yes"}, {"Technical Impact": "partial"}], "version": "2.0.3", "timestamp": "2026-08-04T14:28:25.511403Z"}}}], "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-08-04T14:28:26.525Z"}}], "cna": {"metrics": [{"cvssV3_0": {"version": "3.0", "baseScore": 7.5, "baseSeverity": "HIGH", "vectorString": "CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"}}], "affected": [{"vendor": "nodejs", "product": "node", "versions": [{"status": "affected", "version": "24.18.0", "versionType": "semver", "lessThanOrEqual": "24.18.0"}, {"status": "affected", "version": "22.23.1", "versionType": "semver", "lessThanOrEqual": "22.23.1"}], "defaultStatus": "unaffected"}], "references": [{"url": "https://nodejs.org/en/blog/vulnerability/july-2026-security-releases"}], "descriptions": [{"lang": "en", "value": "A flaw in Node.js HTTP/2 handling can cause HTTP/2 retained header blocks evade maxSessionMemory and enable remote memory exhaustion.\r\n\r\nThis vulnerability affects Node.js **24.x** and **22.x**."}], "problemTypes": [{"descriptions": [{"lang": "en", "type": "CWE", "cweId": "CWE-400", "description": "CWE-400 Uncontrolled Resource Consumption"}]}], "providerMetadata": {"orgId": "36234546-b8fa-4601-9d6f-f4e334aa8ea1", "shortName": "hackerone", "dateUpdated": "2026-08-04T00:49:58.319Z"}}}, "cveMetadata": {"cveId": "CVE-2026-56846", "state": "PUBLISHED", "dateUpdated": "2026-08-04T15:03:38.709Z", "dateReserved": "2026-06-23T15:00:03.632Z", "assignerOrgId": "36234546-b8fa-4601-9d6f-f4e334aa8ea1", "datePublished": "2026-08-04T00:49:58.319Z", "assignerShortName": "hackerone"}, "dataVersion": "5.2"}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "node", "vendor": "nodejs", "versions": [{"lessThanOrEqual": "24.18.0", "status": "affected", "version": "24.18.0", "versionType": "semver"}, {"lessThanOrEqual": "22.23.1", "status": "affected", "version": "22.23.1", "versionType": "semver"}]}], "source": "support@hackerone.com"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "A flaw in Node.js HTTP/2 handling can cause HTTP/2 retained header blocks evade maxSessionMemory and enable remote memory exhaustion.\r\n\r\nThis vulnerability affects Node.js **24.x** and **22.x**."}, {"lang": "es", "value": "Una falla en el manejo de HTTP/2 de Node.js puede causar que los bloques de encabezado HTTP/2 retenidos evadan maxSessionMemory y permitan el agotamiento remoto de memoria.\n\nEsta vulnerabilidad afecta a Node.js 24.x y 22.x."}], "id": "CVE-2026-56846", "lastModified": "2026-10-23T23:10:00.157", "metrics": {"cvssMetricV30": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 7.5, "baseSeverity": "HIGH", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "version": "3.0"}, "exploitabilityScore": 3.9, "impactScore": 3.6, "source": "support@hackerone.com", "type": "Secondary"}], "ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-56846", "options": [{"exploitation": "none"}, {"automatable": "yes"}, {"technicalImpact": "partial"}], "role": "CISA Coordinator", "timestamp": "2026-08-04T14:28:25.511403Z", "version": "2.0.3"}}]}, "published": "2026-08-04T01:16:19.840", "references": [{"source": "support@hackerone.com", "url": "https://nodejs.org/en/blog/vulnerability/july-2026-security-releases"}], "sourceIdentifier": "support@hackerone.com", "vulnStatus": "Awaiting Analysis", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-400"}], "source": "support@hackerone.com", "type": "Secondary"}]}

{"affected_release": [{"advisory": "RHSA-2026:48305", "cpe": "cpe:/a:redhat:hummingbird:1", "package": "nodejs22-main-22.23.2-2.3.hum1", "product_name": "Red Hat Hardened Images", "release_date": "2026-07-29T00:00:00Z"}, {"advisory": "RHSA-2026:48537", "cpe": "cpe:/a:redhat:hummingbird:1", "package": "nodejs24-main-24.18.1-0.1.hum1", "product_name": "Red Hat Hardened Images", "release_date": "2026-07-30T00:00:00Z"}], "bugzilla": {"description": "nodejs: Node.js: Remote memory exhaustion via HTTP/2 retained header blocks", "id": "2510856", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2510856"}, "csaw": false, "cvss3": {"cvss3_base_score": "7.5", "cvss3_scoring_vector": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "status": "verified"}, "cwe": "CWE-400", "details": ["A flaw in Node.js HTTP/2 handling can cause HTTP/2 retained header blocks evade maxSessionMemory and enable remote memory exhaustion.\nThis vulnerability affects Node.js **24.x** and **22.x**.", "A flaw was found in Node.js's handling of HTTP/2. This vulnerability allows a remote attacker to bypass maxSessionMemory limits by sending specially crafted HTTP/2 retained header blocks. This can lead to memory exhaustion, resulting in a denial of service (DoS) for the affected system."], "mitigation": {"lang": "en:us", "value": "To mitigate this issue, restrict network access to Node.js applications utilizing HTTP/2 to trusted clients only, by implementing firewall rules or network access controls. If HTTP/2 functionality is not essential for the application, consider disabling it in the Node.js configuration to prevent exploitation. Always ensure that any service restarts or reloads are performed carefully to avoid service disruption."}, "name": "CVE-2026-56846", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Affected", "package_name": "nodejs22", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Affected", "package_name": "nodejs24", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Affected", "package_name": "nodejs", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Affected", "package_name": "nodejs:22/nodejs", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Affected", "package_name": "nodejs:24/nodejs", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/a:redhat:hummingbird:1", "fix_state": "Not affected", "package_name": "nodejs20", "product_name": "Red Hat Hardened Images"}, {"cpe": "cpe:/a:redhat:hummingbird:1", "fix_state": "Not affected", "package_name": "nodejs25", "product_name": "Red Hat Hardened Images"}, {"cpe": "cpe:/a:redhat:hummingbird:1", "fix_state": "Not affected", "package_name": "nodejs26", "product_name": "Red Hat Hardened Images"}], "public_date": "2026-08-04T00:49:58Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-56846\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-56846\nhttps://nodejs.org/en/blog/vulnerability/july-2026-security-releases"], "statement": "This Important flaw in Node.js HTTP/2 handling allows a remote attacker to bypass `maxSessionMemory` limits by sending specially crafted header blocks. This can lead to memory exhaustion and a denial of service for Node.js applications configured to use HTTP/2, without requiring authentication or user interaction.", "threat_severity": "Important"}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[24.18.0,24.18.0]"}}, {"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[22.23.1,22.23.1]"}}], "enrichment": {"confidence": 92.0, "confidence_source": "matching", "scores": [{"score": 92.0, "source": "matching"}]}, "original": {"product": "node", "source": "cna", "vendor": "nodejs"}, "product": "nodejs", "vendor": "nodejs"}], "created": "2026-08-04T21:45:04.727274+00:00", "title": "Node.js HTTP/2 Memory Exhaustion via Header Block Bypass", "updated": "2026-08-07T09:45:07.164685+00:00", "vendors": ["nodejs", "nodejs$PRODUCT$nodejs"]}