{"cve":"CVE-2026-42505","nvd":{"published":"2026-07-08T17:17:21.497","modified":"2026-10-25T17:10:00.197","status":"Analyzed","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.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N","score":5.3},"cwes":["CWE-201"],"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"],"products":["golang:go"],"source":"nvd","synced_at":"2026-10-25T17:50:06.907763985+00:00"},"epss":{"cve":"CVE-2026-42505","score":0.00382,"percentile":0.31958,"date":"2026-10-25"},"kev":null,"osv":[{"id":"GO-2026-5856","url":"https://osv.dev/vulnerability/GO-2026-5856","summary":"Invoking Encrypted Client Hello privacy leak in crypto/tls","modified":"2026-10-03T10:41:52.186009042Z","packages":[{"ecosystem":"Go","name":"stdlib","purl":"pkg:golang/stdlib","ranges":["<1.25.12",">=1.26.0-0 <1.26.5",">=1.27.0-0 <1.27.0-rc.2"],"fixed":["1.25.12","1.26.5","1.27.0-rc.2"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}