{"id":"CVE-2026-42505","state":"PUBLISHED","title":"Invoking Encrypted Client Hello privacy leak in crypto/tls","description":"Handshakes which used Encrypted Client Hello could be de-anonymized by a passive network observer due to a disclosure of pre-shared key identities in the unencrypted client hello.","publishedAt":"2026-07-08T15:46:33.407Z","updatedAt":"2026-07-08T19:38:17.603Z","severity":{"score":5.3,"label":"Medium","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N","source":"CISA-ADP"},"assigner":"Go","products":["Go standard library crypto/tls"],"affected":[{"vendor":"Go standard library","product":"crypto/tls","packageName":"crypto/tls","defaultStatus":"unaffected","versions":[{"version":"0","status":"affected","lessThan":"1.25.12","versionType":"semver"},{"version":"1.26.0-0","status":"affected","lessThan":"1.26.5","versionType":"semver"},{"version":"1.27.0-0","status":"affected","lessThan":"1.27.0-rc.2","versionType":"semver"}],"collectionURL":"https://pkg.go.dev","programRoutines":[{"name":"clientHelloMsg.marshalMsg"},{"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.SendSessionTicket"},{"name":"QUICConn.Start"}]}],"references":["https://go.dev/cl/775960","https://go.dev/issue/79282","https://groups.google.com/g/golang-announce/c/OrmQE_Yp5Sc","https://pkg.go.dev/vuln/GO-2026-5856"],"weaknesses":["CWE-201"],"ingestedAt":"2026-10-29T20:11:57.932Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/42xxx/CVE-2026-42505.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-42505","state":"PUBLISHED","datePublished":"2026-07-08T15:46:33.407Z","dateUpdated":"2026-07-08T19:38:17.603Z","assignerShortName":"Go","assignerOrgId":"1bb62c36-49e3-4200-9d77-64a1400537cc","dateReserved":"2026-04-28T00:21:12.792Z"},"containers":{"cna":{"title":"Invoking Encrypted Client Hello privacy leak in crypto/tls","descriptions":[{"lang":"en","value":"Handshakes which used Encrypted Client Hello could be de-anonymized by a passive network observer due to a disclosure of pre-shared key identities in the unencrypted client hello."}],"affected":[{"vendor":"Go standard library","product":"crypto/tls","packageName":"crypto/tls","defaultStatus":"unaffected","versions":[{"version":"0","status":"affected","lessThan":"1.25.12","versionType":"semver"},{"version":"1.26.0-0","status":"affected","lessThan":"1.26.5","versionType":"semver"},{"version":"1.27.0-0","status":"affected","lessThan":"1.27.0-rc.2","versionType":"semver"}],"collectionURL":"https://pkg.go.dev","programRoutines":[{"name":"clientHelloMsg.marshalMsg"},{"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.SendSessionTicket"},{"name":"QUICConn.Start"}]}],"references":[{"url":"https://go.dev/cl/775960"},{"url":"https://go.dev/issue/79282"},{"url":"https://groups.google.com/g/golang-announce/c/OrmQE_Yp5Sc"},{"url":"https://pkg.go.dev/vuln/GO-2026-5856"}],"problemTypes":[{"descriptions":[{"lang":"en","description":"CWE-201: Insertion of Sensitive Information Into Sent Data"}]}],"providerMetadata":{"shortName":"Go","orgId":"1bb62c36-49e3-4200-9d77-64a1400537cc","dateUpdated":"2026-07-08T15:46:33.407Z"},"credits":[{"lang":"en","value":"Coia Prant (github.com/rbqvq)"}]},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"cvssV3_1":{"scope":"UNCHANGED","version":"3.1","baseScore":5.3,"attackVector":"NETWORK","baseSeverity":"MEDIUM","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N","integrityImpact":"NONE","userInteraction":"NONE","attackComplexity":"LOW","availabilityImpact":"NONE","privilegesRequired":"NONE","confidentialityImpact":"LOW"}},{"other":{"type":"ssvc","content":{"timestamp":"2026-07-08T18:03:53.821942Z","id":"CVE-2026-42505","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-201","type":"CWE","lang":"en","description":"CWE-201 Insertion of Sensitive Information Into Sent Data"}]}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-07-08T19:38:17.603Z"}}]}}}