{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-123866", "assignerOrgId": "ce714d77-add3-4f53-aff5-83d477b104bb", "state": "PUBLISHED", "assignerShortName": "openjs", "dateReserved": "2026-11-06T16:15:25.978Z", "datePublished": "2026-11-11T18:21:18.538Z", "dateUpdated": "2026-11-11T18:21:18.538Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "ce714d77-add3-4f53-aff5-83d477b104bb", "shortName": "openjs", "dateUpdated": "2026-11-11T18:21:18.538Z"}, "title": "Node.js is vulnerable to HTTP/2 response memory disclosure via a use-after-free during stream teardown", "descriptions": [{"lang": "en", "value": "A use-after-free in Node.js HTTP/2 stream teardown can leak response memory, including the contents of other connections' response buffers, to a peer. When a stream is torn down while a write is still backpressured, for example by a peer RST_STREAM or by the server's own per-stream timeout destroying the stream, the stream's response buffer is freed but a reference to it is still used, so freed or unrelated heap memory is written to the socket instead of the intended response. On Node.js 26.x and 24.x the teardown can be driven purely by a remote peer once the window-size change from 26.9.0 and 24.22.0 is present, and on all supported lines the same defect is reachable through an application-initiated teardown such as a per-stream idle timeout. This vulnerability affects Node.js 26.x, 24.x, and 22.x.", "supportingMedia": [{"type": "text/markdown", "base64": false, "value": "A use-after-free in Node.js HTTP/2 stream teardown can leak response memory, including the contents of other connections' response buffers, to a peer. When a stream is torn down while a write is still backpressured, for example by a peer `RST_STREAM` or by the server's own per-stream timeout destroying the stream, the stream's response buffer is freed but a reference to it is still used, so freed or unrelated heap memory is written to the socket instead of the intended response. On Node.js 26.x and 24.x the teardown can be driven purely by a remote peer once the window-size change from 26.9.0 and 24.22.0 is present, and on all supported lines the same defect is reachable through an application-initiated teardown such as a per-stream idle timeout. This vulnerability affects Node.js 26.x, 24.x, and 22.x."}]}], "credits": [{"lang": "en", "value": "aidan02", "type": "reporter"}, {"lang": "en", "value": "mcollina", "type": "remediation developer"}, {"lang": "en", "value": "aduh95", "type": "coordinator"}], "affected": [{"vendor": "nodejs", "product": "node", "defaultStatus": "unaffected", "versions": [{"version": "0.0.0", "status": "affected", "lessThan": "22.23.5", "versionType": "semver"}, {"version": "23.0.0", "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-416", "description": "Use After Free"}]}], "metrics": [{"format": "CVSS", "cvssV3_0": {"version": "3.0", "vectorString": "CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N", "baseScore": 7.5, "baseSeverity": "HIGH"}}], "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"}}}}

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{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "node", "vendor": "nodejs", "versions": [{"lessThan": "22.23.5", "status": "affected", "version": "0.0.0", "versionType": "semver"}, {"lessThan": "24.22.3", "status": "affected", "version": "23.0.0", "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 use-after-free in Node.js HTTP/2 stream teardown can leak response memory, including the contents of other connections' response buffers, to a peer. When a stream is torn down while a write is still backpressured, for example by a peer RST_STREAM or by the server's own per-stream timeout destroying the stream, the stream's response buffer is freed but a reference to it is still used, so freed or unrelated heap memory is written to the socket instead of the intended response. On Node.js 26.x and 24.x the teardown can be driven purely by a remote peer once the window-size change from 26.9.0 and 24.22.0 is present, and on all supported lines the same defect is reachable through an application-initiated teardown such as a per-stream idle timeout. This vulnerability affects Node.js 26.x, 24.x, and 22.x."}], "id": "CVE-2026-123866", "lastModified": "2026-11-12T19:02:35.830", "metrics": {"cvssMetricV30": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "NONE", "baseScore": 7.5, "baseSeverity": "HIGH", "confidentialityImpact": "HIGH", "integrityImpact": "NONE", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N", "version": "3.0"}, "exploitabilityScore": 3.9, "impactScore": 3.6, "source": "ce714d77-add3-4f53-aff5-83d477b104bb", "type": "Secondary"}]}, "published": "2026-11-11T19:17:33.243", "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-416"}], "source": "ce714d77-add3-4f53-aff5-83d477b104bb", "type": "Secondary"}]}

{"bugzilla": {"description": "nodejs: Node.js: Information disclosure via use-after-free during HTTP/2 stream teardown", "id": "2571844", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2571844"}, "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:H/I:N/A:N", "status": "draft"}, "cwe": "CWE-825", "details": ["A flaw was found in Node.js. A use-after-free vulnerability in the HTTP/2 stream handling mechanism allows for information disclosure. When a stream is terminated while outgoing data is delayed, the server frees the response buffer prematurely while continuing to reference it. A remote attacker can exploit this condition to cause the server to transmit unrelated memory from the heap, potentially exposing sensitive data belonging to other user connections."], "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-2026-123866", "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": "2026-11-11T18:21:18Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-123866\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-123866\nhttps://cna.openjsf.org/security-advisories.html\nhttps://nodejs.org/en/blog/vulnerability/november-2026-security-releases"], "statement": "This vulnerability is classified as an Important severity flaw because an unauthenticated remote attacker can trigger memory disclosure across active connections, potentially exposing confidential data from other users' sessions. In Red Hat environments, impact is limited to applications that explicitly enable and expose HTTP/2 services, whereas deployments using standard HTTP/1.1 interfaces are unaffected. Under vulnerable configurations, abrupt stream terminations during pending writes allow freed memory segments to be returned over the network socket.", "threat_severity": "Important"}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[0.0.0,22.23.5)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[23.0.0,24.22.3)"}}, {"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": "2026-11-12T13:45:03.648832+00:00", "updated": "2026-11-12T18:30:06.847500+00:00", "vendors": ["nodejs", "nodejs$PRODUCT$nodejs"]}