CVE-2026-97031Reject malformed ECH outer extension references in crypto/tls
Updated under an hour ago ()
Does this affect you?
It affects Go standard library crypto/tls. Add what you run to find out whether that includes you.
EPSS puts the chance of exploitation in the next 30 days at 0.39%, higher than 32% of scored CVEs.
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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.
- CVSS
- 7.5 HIGH (v3.1, CISA ADP)CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- Weakness (CWE)
- CWE-405
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- 0.39% (percentile 32)
- Assigned by
- Go
- NVD analysis
- Awaiting Analysis
- Record last updated
- Oct 9, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
Go standard library crypto/tls go_standard_library:crypto_tls (from the name) | before 1.26.9; from 1.27.0-0 before 1.27.2 | CNA record |
References
- https://go.dev/cl/847312
- https://go.dev/issue/81855
- https://groups.google.com/g/golang-announce/c/U2fTuyDJznI
- https://pkg.go.dev/vuln/GO-2026-6607
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.