CVE Catalog

CVE-2026-97031

HighCVSS 7.5
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.18%

7th percentile - higher than 7% of all known CVEs

Summary

Multiple ECH outer extension references are not permitted under RFC 9849. Previously, a client could send a crafted packet with multiple references, causing memory exhaustion. Now such packets are rejected as malformed, curbing the memory amplification vector.

Risk Assessment

The attack could lead to server memory exhaustion, causing denial of service. The fix eliminates this risk.

Recommendation

Apply vendor patches that reject malformed ECH packets. Ensure the server is updated.

Related vulnerabilities

Original NVD description (English source)

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.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS