{"id":"CVE-2026-97031","sourceIdentifier":"security@golang.org","published":"2026-10-08T23:17:06.037","lastModified":"2026-10-09T16:35:35.900","vulnStatus":"Awaiting Analysis","cveTags":[],"descriptions":[{"lang":"en","value":"Multiple ECH outer extension references are not permitted under RFC 9849; previously, a client could send a well-crafted packet that could trigger memory exhaustion in the server process by specifying multiple references. We now reject these as malformed and curb the memory amplification vector as a result."}],"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":"decodeInnerClientHello"},{"name":"Conn.Handshake"},{"name":"Conn.HandshakeContext"},{"name":"Conn.Read"},{"name":"Conn.Write"},{"name":"Dial"},{"name":"DialWithDialer"},{"name":"Dialer.Dial"},{"name":"Dialer.DialContext"},{"name":"QUICConn.Start"}],"versions":[{"version":"0","lessThan":"1.26.9","versionType":"semver","status":"affected"},{"version":"1.27.0-0","lessThan":"1.27.2","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":"2026-10-09T15:59:09.530145Z","id":"CVE-2026-97031","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-405"}]}],"references":[{"url":"https://go.dev/cl/847312","source":"security@golang.org"},{"url":"https://go.dev/issue/81855","source":"security@golang.org"},{"url":"https://groups.google.com/g/golang-announce/c/U2fTuyDJznI","source":"security@golang.org"},{"url":"https://pkg.go.dev/vuln/GO-2026-6607","source":"security@golang.org"}]}