CVE-2026-97031
High
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.
SeverityHigh
CVSS7.5
Exploit probability—
Product
Stdlib
PublishedOct 8, 2026
First seenOct 8, 2026
Weakness typeCWE-405CWE-405
How to fix
Update
- stdlib1.26.9, 1.27.2 or later
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| stdlibGo | v < 1.26.9, 1.27.0-0 ≤ v < 1.27.2 | 1.26.9, 1.27.2 |
| microsoft azl3_golang_1.26.7-1 | No range specified | — |
| microsoft azl3_golang_1.27.1-1 | No range specified | — |
| microsoft azl3_golang_1.26.10-1 | No range specified | — |
| microsoft azl3_golang_1.27.3-1 | No range specified | — |
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