{"cve":"CVE-2026-97031","nvd":{"published":"2026-10-08T23:17:06.037","modified":"2026-10-09T16:35:35.900","status":"Awaiting Analysis","description":"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.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","score":7.5},"cwes":["CWE-405"],"references":["https://go.dev/cl/847312","https://go.dev/issue/81855","https://groups.google.com/g/golang-announce/c/U2fTuyDJznI","https://pkg.go.dev/vuln/GO-2026-6607"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:58:01.639778232+00:00"},"epss":{"cve":"CVE-2026-97031","score":0.00519,"percentile":0.43798,"date":"2026-10-25"},"kev":null,"osv":[{"id":"GO-2026-6607","url":"https://osv.dev/vulnerability/GO-2026-6607","summary":"Reject malformed ECH outer extension references in crypto/tls","modified":"2026-10-16T09:55:33.249742867Z","packages":[{"ecosystem":"Go","name":"stdlib","purl":"pkg:golang/stdlib","ranges":["<1.26.9",">=1.27.0-0 <1.27.2"],"fixed":["1.26.9","1.27.2"]}]}],"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."]}