{"id":"CVE-2026-56862","sourceIdentifier":"security@golang.org","published":"2026-08-13T22:17:22.550","lastModified":"2026-10-24T16:10:00.153","vulnStatus":"Awaiting Analysis","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."},{"lang":"es","value":"Los mensajes de handshake, como KeyUpdate, siempre se consideran que avanzan el estado, independientemente de si un handshake se ha completado o no. Como resultado, un cliente malicioso puede seguir enviando mensajes KeyUpdate para forzar al servidor a seguir realizando operaciones de derivación de claves indefinidamente."}],"affected":[{"source":"security@golang.org","affectedData":[{"vendor":"Go standard library","product":"crypto/tls","defaultStatus":"unaffected","collectionURL":"https://pkg.go.dev","packageName":"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"}],"versions":[{"version":"0","lessThan":"1.25.13","versionType":"semver","status":"affected"},{"version":"1.26.0-0","lessThan":"1.26.6","versionType":"semver","status":"affected"},{"version":"1.27.0-0","lessThan":"1.27.0-rc.3","versionType":"semver","status":"affected"}]}]}],"metrics":{"cvssMetricV31":[{"source":"134c704f-9b21-4f2e-91b3-4a467353bcc0","type":"Secondary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","baseScore":7.5,"baseSeverity":"HIGH","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"NONE","integrityImpact":"NONE","availabilityImpact":"HIGH"},"exploitabilityScore":3.9,"impactScore":3.6}],"ssvcV203":[{"source":"134c704f-9b21-4f2e-91b3-4a467353bcc0","ssvcData":{"timestamp":"2026-08-14T15:27:34.651997Z","id":"CVE-2026-56862","options":[{"exploitation":"none"},{"automatable":"yes"},{"technicalImpact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}]},"weaknesses":[{"source":"134c704f-9b21-4f2e-91b3-4a467353bcc0","type":"Secondary","description":[{"lang":"en","value":"CWE-770"}]}],"references":[{"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","source":"security@golang.org"}]}