{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-56862", "assignerOrgId": "1bb62c36-49e3-4200-9d77-64a1400537cc", "state": "PUBLISHED", "assignerShortName": "Go", "dateReserved": "2026-06-23T15:10:49.353Z", "datePublished": "2026-08-13T21:58:53.216Z", "dateUpdated": "2026-08-13T21:58:53.216Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "1bb62c36-49e3-4200-9d77-64a1400537cc", "shortName": "Go", "dateUpdated": "2026-08-13T21:58:53.216Z"}, "title": "Limit handshake messages we are willing to accept post-handshake in crypto/tls", "descriptions": [{"lang": "en", "value": "Handshake messages, such as KeyUpdate, are always considered as state-advancing, regardless of whether a handshake has been completed or not. As a result, a malicious client can keep sending KeyUpdate messages to force the server to keep performing key derivation operations indefinitely."}], "affected": [{"vendor": "Go standard library", "product": "crypto/tls", "collectionURL": "https://pkg.go.dev", "packageName": "crypto/tls", "versions": [{"version": "0", "lessThan": "1.25.13", "status": "affected", "versionType": "semver"}, {"version": "1.26.0-0", "lessThan": "1.26.6", "status": "affected", "versionType": "semver"}, {"version": "1.27.0-0", "lessThan": "1.27.0-rc.3", "status": "affected", "versionType": "semver"}], "programRoutines": [{"name": "Conn.readRecordOrCCS"}, {"name": "Conn.Handshake"}, {"name": "Conn.HandshakeContext"}, {"name": "Conn.Read"}, {"name": "Conn.Write"}, {"name": "Dial"}, {"name": "DialWithDialer"}, {"name": "Dialer.Dial"}, {"name": "Dialer.DialContext"}, {"name": "QUICConn.HandleData"}, {"name": "QUICConn.Start"}], "defaultStatus": "unaffected"}], "problemTypes": [{"descriptions": [{"lang": "en", "description": "CWE-770: Allocation of Resources Without Limits or Throttling"}]}], "references": [{"url": "https://go.dev/issue/80528"}, {"url": "https://go.dev/cl/804261"}, {"url": "https://groups.google.com/g/golang-announce/c/94pEornpRlI"}, {"url": "https://pkg.go.dev/vuln/GO-2026-6090"}], "credits": [{"lang": "en", "value": "Qi Deng of Aurascape.ai"}]}}}

{}

{"affected": [{"affectedData": [{"collectionURL": "https://pkg.go.dev", "defaultStatus": "unaffected", "packageName": "crypto/tls", "product": "crypto/tls", "programRoutines": [{"name": "Conn.readRecordOrCCS"}, {"name": "Conn.Handshake"}, {"name": "Conn.HandshakeContext"}, {"name": "Conn.Read"}, {"name": "Conn.Write"}, {"name": "Dial"}, {"name": "DialWithDialer"}, {"name": "Dialer.Dial"}, {"name": "Dialer.DialContext"}, {"name": "QUICConn.HandleData"}, {"name": "QUICConn.Start"}], "vendor": "Go standard library", "versions": [{"lessThan": "1.25.13", "status": "affected", "version": "0", "versionType": "semver"}, {"lessThan": "1.26.6", "status": "affected", "version": "1.26.0-0", "versionType": "semver"}, {"lessThan": "1.27.0-rc.3", "status": "affected", "version": "1.27.0-0", "versionType": "semver"}]}], "source": "security@golang.org"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "Handshake messages, such as KeyUpdate, are always considered as state-advancing, regardless of whether a handshake has been completed or not. As a result, a malicious client can keep sending KeyUpdate messages to force the server to keep performing key derivation operations indefinitely."}], "id": "CVE-2026-56862", "lastModified": "2026-08-13T22:17:22.550", "metrics": {}, "published": "2026-08-13T22:17:22.550", "references": [{"source": "security@golang.org", "url": "https://go.dev/cl/804261"}, {"source": "security@golang.org", "url": "https://go.dev/issue/80528"}, {"source": "security@golang.org", "url": "https://groups.google.com/g/golang-announce/c/94pEornpRlI"}, {"source": "security@golang.org", "url": "https://pkg.go.dev/vuln/GO-2026-6090"}], "sourceIdentifier": "security@golang.org", "vulnStatus": "Received"}

{}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "generic", "value": "[0,1.25.13)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[1.26.0-0,1.26.6)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[1.27.0-0,1.27.0-rc.3)"}}], "enrichment": {"confidence": 100.0, "confidence_source": "matching", "scores": [{"score": 100.0, "source": "matching"}]}, "original": {"product": "crypto/tls", "source": "cna", "vendor": "Go standard library"}, "product": "crypto_tls", "vendor": "go_standard_library"}], "created": "2026-08-13T23:30:02.807564+00:00", "updated": "2026-08-13T23:30:02.807588+00:00", "vendors": ["go_standard_library", "go_standard_library$PRODUCT$crypto_tls"]}