Vulnerability-Lookup

GHSA-FF52-PH69-CF7X

Vulnerability from github – Published: 2026-07-08 18:31 – Updated: 2026-07-08 21:30

Details

Handshakes which used Encrypted Client Hello could be de-anonymized by a passive network observer due to a disclosure of pre-shared key identities in the unencrypted client hello.

Severity

5.3 (Medium)


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

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JSON

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{
  "affected": [],
  "aliases": [
    "CVE-2026-42505"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-201"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-07-08T17:17:21Z",
    "severity": "MODERATE"
  },
  "details": "Handshakes which used Encrypted Client Hello could be de-anonymized by a passive network observer due to a disclosure of pre-shared key identities in the unencrypted client hello.",
  "id": "GHSA-ff52-ph69-cf7x",
  "modified": "2026-07-08T21:30:27Z",
  "published": "2026-07-08T18:31:37Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-42505"
    },
    {
      "type": "WEB",
      "url": "https://go.dev/cl/775960"
    },
    {
      "type": "WEB",
      "url": "https://go.dev/issue/79282"
    },
    {
      "type": "WEB",
      "url": "https://groups.google.com/g/golang-announce/c/OrmQE_Yp5Sc"
    },
    {
      "type": "WEB",
      "url": "https://pkg.go.dev/vuln/GO-2026-5856"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N",
      "type": "CVSS_V3"
    }
  ]
}

CVE-2026-42505 (GCVE-0-2026-42505)

Vulnerability from cvelistv5 – Published: 2026-07-08 15:46 – Updated: 2026-07-08 19:38

Title

Invoking Encrypted Client Hello privacy leak in crypto/tls

Summary

Handshakes which used Encrypted Client Hello could be de-anonymized by a passive network observer due to a disclosure of pre-shared key identities in the unencrypted client hello.

Severity

5.3 (Medium)


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

SSVC

Exploitation: none Automatable: yes Technical Impact: partial

CISA Coordinator (v2.0.3)

CWE

CWE-201 - Insertion of Sensitive Information Into Sent Data

Assigner

References

4 references

URL	Tags
https://go.dev/cl/775960
https://go.dev/issue/79282
https://groups.google.com/g/golang-announce/c/Orm…
https://pkg.go.dev/vuln/GO-2026-5856

Impacted products

1 product

Vendor	Product	Version
Go standard library	crypto/tls	Affected: 0 , < 1.25.12 (semver) Affected: 1.26.0-0 , < 1.26.5 (semver) Affected: 1.27.0-0 , < 1.27.0-rc.2 (semver)

Credits

Coia Prant (github.com/rbqvq)

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JSON

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{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "cvssV3_1": {
              "attackComplexity": "LOW",
              "attackVector": "NETWORK",
              "availabilityImpact": "NONE",
              "baseScore": 5.3,
              "baseSeverity": "MEDIUM",
              "confidentialityImpact": "LOW",
              "integrityImpact": "NONE",
              "privilegesRequired": "NONE",
              "scope": "UNCHANGED",
              "userInteraction": "NONE",
              "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N",
              "version": "3.1"
            }
          },
          {
            "other": {
              "content": {
                "id": "CVE-2026-42505",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-07-08T18:03:53.821942Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "problemTypes": [
          {
            "descriptions": [
              {
                "cweId": "CWE-201",
                "description": "CWE-201 Insertion of Sensitive Information Into Sent Data",
                "lang": "en",
                "type": "CWE"
              }
            ]
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-07-08T19:38:17.603Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "collectionURL": "https://pkg.go.dev",
          "defaultStatus": "unaffected",
          "packageName": "crypto/tls",
          "product": "crypto/tls",
          "programRoutines": [
            {
              "name": "clientHelloMsg.marshalMsg"
            },
            {
              "name": "Conn.Handshake"
            },
            {
              "name": "Conn.HandshakeContext"
            },
            {
              "name": "Conn.Read"
            },
            {
              "name": "Conn.Write"
            },
            {
              "name": "Dial"
            },
            {
              "name": "DialWithDialer"
            },
            {
              "name": "Dialer.Dial"
            },
            {
              "name": "Dialer.DialContext"
            },
            {
              "name": "QUICConn.HandleData"
            },
            {
              "name": "QUICConn.SendSessionTicket"
            },
            {
              "name": "QUICConn.Start"
            }
          ],
          "vendor": "Go standard library",
          "versions": [
            {
              "lessThan": "1.25.12",
              "status": "affected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThan": "1.26.5",
              "status": "affected",
              "version": "1.26.0-0",
              "versionType": "semver"
            },
            {
              "lessThan": "1.27.0-rc.2",
              "status": "affected",
              "version": "1.27.0-0",
              "versionType": "semver"
            }
          ]
        }
      ],
      "credits": [
        {
          "lang": "en",
          "value": "Coia Prant (github.com/rbqvq)"
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "Handshakes which used Encrypted Client Hello could be de-anonymized by a passive network observer due to a disclosure of pre-shared key identities in the unencrypted client hello."
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "description": "CWE-201: Insertion of Sensitive Information Into Sent Data",
              "lang": "en"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-07-08T15:46:33.407Z",
        "orgId": "1bb62c36-49e3-4200-9d77-64a1400537cc",
        "shortName": "Go"
      },
      "references": [
        {
          "url": "https://go.dev/cl/775960"
        },
        {
          "url": "https://go.dev/issue/79282"
        },
        {
          "url": "https://groups.google.com/g/golang-announce/c/OrmQE_Yp5Sc"
        },
        {
          "url": "https://pkg.go.dev/vuln/GO-2026-5856"
        }
      ],
      "title": "Invoking Encrypted Client Hello privacy leak in crypto/tls"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "1bb62c36-49e3-4200-9d77-64a1400537cc",
    "assignerShortName": "Go",
    "cveId": "CVE-2026-42505",
    "datePublished": "2026-07-08T15:46:33.407Z",
    "dateReserved": "2026-04-28T00:21:12.792Z",
    "dateUpdated": "2026-07-08T19:38:17.603Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
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.

Detection rules are retrieved from Rulezet.

Action not permitted

GHSA-FF52-PH69-CF7X

CVE-2026-42505 (GCVE-0-2026-42505)

Tags

Sightings

Nomenclature