What is CVE-2026-97031?

CVE-2026-97031 is a high-severity vulnerability in Go Standard Library Crypto/tls, classified under Asymmetric Resource Consumption (Amplification). CVSS score: 7.5/10. Published 2026-10-08.

How severe is CVE-2026-97031?

High severity. CVSS v3 base score is 7.5 out of 10.

Vulnerability in Go Standard Library Crypto/tls

CVE-2026-97031

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.

Published 2026-10-08 · last modified 2026-10-09.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

EPSS exploit prediction

No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.

Affected products

Go Standard Library Crypto/tls

Weakness classification (CWE)

CWE-405 — Asymmetric Resource Consumption (Amplification)

References

Frequently asked questions

What is CVE-2026-97031?: CVE-2026-97031 is a high-severity vulnerability in Go Standard Library Crypto/tls, classified under Asymmetric Resource Consumption (Amplification). CVSS score: 7.5/10. Published 2026-10-08.
How severe is CVE-2026-97031?: High severity. CVSS v3 base score is 7.5 out of 10.