Vulnerability Intelligence Report
Reject malformed ECH outer extension references in 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.
No Active Exploit Signals
CVSS Base Score
7.5
HIGH
Exploitability:3.9
Impact Score:3.6
EPSS Probability:0.18%
Executive Threat Verdict
Evaluating...
Evaluating Threat Landscape...
Assessing known weaponization, exploitation telemetry, and federal advisories.
Attack Surface
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Authentication
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Weaponization
—
SSVC Action
—
Weaknesses (CWE)
CWE-405 ↗CWE-405: Asymmetric Resource Consumption
Affected Products & Versions
| Vendor | Product | Affected Versions |
|---|---|---|
| Go standard library | crypto/tls | 0 < 1.26.9 (affected), 1.27.0-0 < 1.27.2 (affected) |
References & Technical Advisories
No reference links found.
Threat Intelligence Signals
EPSS Score
0.179%
GitHub Advisory
Identity & Timeline
| Status | PUBLISHED |
| Assigning Authority | Go Project · Vendor · USA |
| Reserved | 2026-09-23T23:03:36 |
| Published | 2026-10-08T22:53:58 |
| Last Updated | 2026-10-09T15:59:17 |
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