CVE-2026-97031 | BDVDB-2026-384644 Detail

Go standard librarycrypto/tls

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.

Impact#

Per CVSS v3.1: confidentiality impact none, integrity impact none, availability impact high. Attack vector: network.

Weaknesses#

CWE-405 Asymmetric Resource Consumption

References#

Exploit#

No public exploit known

History#

Version 12026-10-08Record published in the CVE List.
Version 22026-10-09Most recent update recorded in the CVE List.

Published

Published: 2026-10-08
Last modified: 2026-10-09

Vendor information

Vendor: Go standard library
Product: crypto/tls

All Go standard library vulnerabilities

Score

7.5 High

EPSS

less than 1%, Very Low

Estimated chance of exploitation in the next 30 days. EPSS percentile: 54.1.

KEV

Not listed in the CISA Known Exploited Vulnerabilities catalog.

Impact

Not classified

Action

No specific action is recorded in the source data. Check the references for vendor guidance.

Affected Systems

Vulnerable
< 1.26.9
Fixed
1.26.9
Vulnerable
>= 1.27.0-0 and < 1.27.2
Fixed
1.27.2

Scoring System

CVSS v4.0

Not available

CVSS v3.1

7.5 High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Metric breakdown
Attack Vector	Network
Attack Complexity	Low
Privileges Required	None
User Interaction	None
Scope	Unchanged
Confidentiality	None
Integrity	None
Availability	High

CVSS v3.0

Not available

CVSS v2

Not available

Source: CVE List v5 (record); CISA KEV (kev, action); FIRST EPSS (epss).