CVE-2026-123828

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-123828", "assignerOrgId": "ce714d77-add3-4f53-aff5-83d477b104bb", "state": "PUBLISHED", "assignerShortName": "openjs", "dateReserved": "2026-11-06T16:02:55.733Z", "datePublished": "2026-11-11T18:10:54.030Z", "dateUpdated": "2026-11-11T18:10:54.030Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "ce714d77-add3-4f53-aff5-83d477b104bb", "shortName": "openjs", "dateUpdated": "2026-11-11T18:10:54.030Z"}, "title": "Node.js is vulnerable to a heap buffer overflow in HTTP/2 session.altsvc() via a long origin", "descriptions": [{"lang": "en", "value": "A one-byte heap buffer overflow in Node.js HTTP/2 Alt-Svc handling lets a remote, unauthenticated attacker corrupt process memory. When an application passes an attacker-controlled value such as a request's :authority header to Http2Session.altsvc(), the AltSvc implementation in src/node_http2.cc allocates a buffer sized to the origin length and then writes it with a null terminator, placing one byte past the end of the allocation. A single request carrying a long but syntactically valid :authority triggers the out-of-bounds write, which aborts the process and serves as a remote heap-corruption primitive. This vulnerability affects Node.js 26.x and 24.x.", "supportingMedia": [{"type": "text/markdown", "base64": false, "value": "A one-byte heap buffer overflow in Node.js HTTP/2 Alt-Svc handling lets a remote, unauthenticated attacker corrupt process memory. When an application passes an attacker-controlled value such as a request's `:authority` header to `Http2Session.altsvc()`, the AltSvc implementation in `src/node_http2.cc` allocates a buffer sized to the origin length and then writes it with a null terminator, placing one byte past the end of the allocation. A single request carrying a long but syntactically valid `:authority` triggers the out-of-bounds write, which aborts the process and serves as a remote heap-corruption primitive. This vulnerability affects Node.js 26.x and 24.x."}]}], "credits": [{"lang": "en", "value": "zonduu", "type": "reporter"}, {"lang": "en", "value": "mcollina", "type": "remediation developer"}, {"lang": "en", "value": "UlisesGascon", "type": "remediation reviewer"}, {"lang": "en", "value": "pimterry", "type": "remediation reviewer"}, {"lang": "en", "value": "aduh95", "type": "coordinator"}], "affected": [{"vendor": "nodejs", "product": "node", "defaultStatus": "unaffected", "versions": [{"version": "24.0.0", "status": "affected", "lessThan": "24.22.3", "versionType": "semver"}, {"version": "25.0.0", "status": "affected", "lessThan": "26.13.1", "versionType": "semver"}]}], "problemTypes": [{"descriptions": [{"lang": "en", "type": "CWE", "cweId": "CWE-122", "description": "Heap Overflow"}]}], "metrics": [{"format": "CVSS", "cvssV3_0": {"version": "3.0", "vectorString": "CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H", "baseScore": 5.9, "baseSeverity": "MEDIUM"}}], "references": [{"url": "https://nodejs.org/en/blog/vulnerability/november-2026-security-releases", "tags": ["vendor-advisory"]}, {"url": "https://cna.openjsf.org/security-advisories.html"}], "x_generator": {"engine": "nodejs-private/security-release publish-cves"}}}}

{}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "node", "vendor": "nodejs", "versions": [{"lessThan": "24.22.3", "status": "affected", "version": "24.0.0", "versionType": "semver"}, {"lessThan": "26.13.1", "status": "affected", "version": "25.0.0", "versionType": "semver"}]}], "source": "ce714d77-add3-4f53-aff5-83d477b104bb"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "A one-byte heap buffer overflow in Node.js HTTP/2 Alt-Svc handling lets a remote, unauthenticated attacker corrupt process memory. When an application passes an attacker-controlled value such as a request's :authority header to Http2Session.altsvc(), the AltSvc implementation in src/node_http2.cc allocates a buffer sized to the origin length and then writes it with a null terminator, placing one byte past the end of the allocation. A single request carrying a long but syntactically valid :authority triggers the out-of-bounds write, which aborts the process and serves as a remote heap-corruption primitive. This vulnerability affects Node.js 26.x and 24.x."}], "id": "CVE-2026-123828", "lastModified": "2026-11-12T19:02:35.830", "metrics": {"cvssMetricV30": [{"cvssData": {"attackComplexity": "HIGH", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 5.9, "baseSeverity": "MEDIUM", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H", "version": "3.0"}, "exploitabilityScore": 2.2, "impactScore": 3.6, "source": "ce714d77-add3-4f53-aff5-83d477b104bb", "type": "Secondary"}]}, "published": "2026-11-11T19:17:30.740", "references": [{"source": "ce714d77-add3-4f53-aff5-83d477b104bb", "url": "https://cna.openjsf.org/security-advisories.html"}, {"source": "ce714d77-add3-4f53-aff5-83d477b104bb", "url": "https://nodejs.org/en/blog/vulnerability/november-2026-security-releases"}], "sourceIdentifier": "ce714d77-add3-4f53-aff5-83d477b104bb", "vulnStatus": "Awaiting Analysis", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-122"}], "source": "ce714d77-add3-4f53-aff5-83d477b104bb", "type": "Secondary"}]}

{"bugzilla": {"description": "nodejs: nodejs: Denial of Service via HTTP/2 Alt-Svc heap buffer overflow", "id": "2571813", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2571813"}, "csaw": false, "cvss3": {"cvss3_base_score": "5.9", "cvss3_scoring_vector": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H", "status": "draft"}, "cwe": "CWE-787", "details": ["A flaw was found in Node.js. A remote, unauthenticated attacker can cause a Denial of Service (DoS) by sending a specially crafted request with an oversized header to an application that processes HTTP/2 Alternative Services (Alt-Svc). Due to an off-by-one heap buffer overflow, the application writes one byte past the allocated memory buffer, corrupting process memory and causing the server to crash."], "mitigation": {"lang": "en:us", "value": "Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability."}, "name": "CVE-2026-123828", "package_state": [{"cpe": "cpe:/a:redhat:hummingbird:1", "fix_state": "Will not fix", "package_name": "nodejs20", "product_name": "Red Hat Hardened Images"}, {"cpe": "cpe:/a:redhat:hummingbird:1", "fix_state": "Affected", "package_name": "nodejs22", "product_name": "Red Hat Hardened Images"}, {"cpe": "cpe:/a:redhat:hummingbird:1", "fix_state": "Affected", "package_name": "nodejs24", "product_name": "Red Hat Hardened Images"}, {"cpe": "cpe:/a:redhat:hummingbird:1", "fix_state": "Will not fix", "package_name": "nodejs25", "product_name": "Red Hat Hardened Images"}, {"cpe": "cpe:/a:redhat:hummingbird:1", "fix_state": "Affected", "package_name": "nodejs26", "product_name": "Red Hat Hardened Images"}], "public_date": "2026-11-11T18:10:54Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-123828\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-123828\nhttps://cna.openjsf.org/security-advisories.html\nhttps://nodejs.org/en/blog/vulnerability/november-2026-security-releases"], "statement": "Red Hat has evaluated this vulnerability as Moderate severity because exploitation requires specific application-level code to process untrusted input through the HTTP/2 Alternative Services API, limiting broad exposure despite potential process crashes. Standard deployments do not automatically pass client-controlled headers to this interface. The flaw primarily presents an availability risk through application termination rather than arbitrary code execution under standard runtime protections.", "threat_severity": "Moderate"}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[24.0.0,24.22.3)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[25.0.0,26.13.1)"}}], "enrichment": {"confidence": 100.0, "confidence_source": "matching", "scores": [{"score": 100.0, "source": "matching"}]}, "original": {"product": "node", "source": "cna", "vendor": "nodejs"}, "product": "nodejs", "vendor": "nodejs"}], "created": "2026-11-12T14:00:03.701645+00:00", "updated": "2026-11-12T18:30:06.851779+00:00", "vendors": ["nodejs", "nodejs$PRODUCT$nodejs"]}