Vulnerability-Lookup

GHSA-HQ7W-2XRQ-WP2J

Vulnerability from github – Published: 2026-10-09 00:31 – Updated: 2026-10-09 00:31

Details

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.

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{
  "affected": [],
  "aliases": [
    "CVE-2026-97031"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-10-08T23:17:06Z",
    "severity": null
  },
  "details": "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.",
  "id": "GHSA-hq7w-2xrq-wp2j",
  "modified": "2026-10-09T00:31:49Z",
  "published": "2026-10-09T00:31:49Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-97031"
    },
    {
      "type": "WEB",
      "url": "https://go.dev/cl/847312"
    },
    {
      "type": "WEB",
      "url": "https://go.dev/issue/81855"
    },
    {
      "type": "WEB",
      "url": "https://groups.google.com/g/golang-announce/c/U2fTuyDJznI"
    },
    {
      "type": "WEB",
      "url": "https://pkg.go.dev/vuln/GO-2026-6607"
    }
  ],
  "schema_version": "1.4.0",
  "severity": []
}

CVE-2026-97031 (GCVE-0-2026-97031)

Vulnerability from cvelistv5 – Published: 2026-10-08 22:53 – Updated: 2026-10-08 22:53

Title

Reject malformed ECH outer extension references in crypto/tls

Summary

Severity

No CVSS data available.

CWE

CWE-405 - Asymmetric Resource Consumption

Assigner

Go CNA under the Google root

CNA scorecard E 42/100 over 75 records in the last 180 days details

References

4 references

URL	Tags
https://go.dev/cl/847312
https://go.dev/issue/81855
https://groups.google.com/g/golang-announce/c/U2f…
https://pkg.go.dev/vuln/GO-2026-6607

Impacted products

1 product

Vendor	Product	Version
Go standard library	crypto/tls	Affected: 0 , < 1.26.9 (semver) Affected: 1.27.0-0 , < 1.27.2 (semver)

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{
  "containers": {
    "cna": {
      "affected": [
        {
          "collectionURL": "https://pkg.go.dev",
          "defaultStatus": "unaffected",
          "packageName": "crypto/tls",
          "product": "crypto/tls",
          "programRoutines": [
            {
              "name": "decodeInnerClientHello"
            },
            {
              "name": "Conn.Handshake"
            },
            {
              "name": "Conn.HandshakeContext"
            },
            {
              "name": "Conn.Read"
            },
            {
              "name": "Conn.Write"
            },
            {
              "name": "Dial"
            },
            {
              "name": "DialWithDialer"
            },
            {
              "name": "Dialer.Dial"
            },
            {
              "name": "Dialer.DialContext"
            },
            {
              "name": "QUICConn.Start"
            }
          ],
          "vendor": "Go standard library",
          "versions": [
            {
              "lessThan": "1.26.9",
              "status": "affected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThan": "1.27.2",
              "status": "affected",
              "version": "1.27.0-0",
              "versionType": "semver"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "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."
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "description": "CWE-405: Asymmetric Resource Consumption",
              "lang": "en"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-10-08T22:53:58.775Z",
        "orgId": "1bb62c36-49e3-4200-9d77-64a1400537cc",
        "shortName": "Go"
      },
      "references": [
        {
          "url": "https://go.dev/cl/847312"
        },
        {
          "url": "https://go.dev/issue/81855"
        },
        {
          "url": "https://groups.google.com/g/golang-announce/c/U2fTuyDJznI"
        },
        {
          "url": "https://pkg.go.dev/vuln/GO-2026-6607"
        }
      ],
      "title": "Reject malformed ECH outer extension references in crypto/tls"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "1bb62c36-49e3-4200-9d77-64a1400537cc",
    "assignerShortName": "Go",
    "cveId": "CVE-2026-97031",
    "datePublished": "2026-10-08T22:53:58.775Z",
    "dateReserved": "2026-09-23T23:03:36.988Z",
    "dateUpdated": "2026-10-08T22:53:58.775Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

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Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
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GHSA-HQ7W-2XRQ-WP2J

CVE-2026-97031 (GCVE-0-2026-97031)

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Sightings

Nomenclature

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