FKIE_CVE-2026-35188

Vulnerability from fkie_nvd - Published: 2026-06-09 17:17 - Updated: 2026-06-10 22:16
Severity
5.0 (Medium) - CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:L
Summary
Issue summary: A malicious server can exploit TLS OCSP stapling by delivering a crafted response through the status_request extension, triggering a double-free in the client's certificate verification path. Impact summary: Successful exploitation allows an attacker to corrupt heap memory via a double-free, potentially leading to a Denial of Service or possibly an attacker controlled code execution or other undefined behavior. If OCSP stapling is enabled and the TLS client connects to a malicious server, a crafted OCSP stapled response can trigger a double free in the TLS client when the stapled response is checked. The OCSP stapling is not enabled by default. Reliable code execution through a double-free is technically complex and highly environment-dependent but the Denial of Service impact is straightforward to achieve, warranting Moderate severity. No FIPS modules are affected by this issue as the affected code is outside the OpenSSL FIPS module boundary.
References
openssl-security@openssl.orghttps://github.com/openssl/openssl/commit/131145d25659e8749a9ed1afb383484854cffb78
openssl-security@openssl.orghttps://github.com/openssl/openssl/commit/78d0154cffda03aaaac63a087cc523a6b35fa8fd
openssl-security@openssl.orghttps://openssl-library.org/news/secadv/20260609.txt
Impacted products
Vendor Product Version
To clipboard 

{
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "Issue summary: A malicious server can exploit TLS OCSP stapling by delivering\na crafted response through the status_request extension, triggering a\ndouble-free in the client\u0027s certificate verification path.\n\nImpact summary: Successful exploitation allows an attacker to corrupt heap\nmemory via a double-free, potentially leading to a Denial of Service or\npossibly an attacker controlled code execution or other undefined behavior.\n\nIf OCSP stapling is enabled and the TLS client connects to a malicious server,\na crafted OCSP stapled response can trigger a double free in the TLS client\nwhen the stapled response is checked.\n\nThe OCSP stapling is not enabled by default. Reliable code execution\nthrough a double-free is technically complex and highly environment-dependent\nbut the Denial of Service impact is straightforward to achieve, warranting\nModerate severity.\n\nNo FIPS modules are affected by this issue as the affected code is outside\nthe OpenSSL FIPS module boundary."
    }
  ],
  "id": "CVE-2026-35188",
  "lastModified": "2026-06-10T22:16:56.973",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "HIGH",
          "attackVector": "NETWORK",
          "availabilityImpact": "LOW",
          "baseScore": 5.0,
          "baseSeverity": "MEDIUM",
          "confidentialityImpact": "LOW",
          "integrityImpact": "LOW",
          "privilegesRequired": "LOW",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:L",
          "version": "3.1"
        },
        "exploitabilityScore": 1.6,
        "impactScore": 3.4,
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "type": "Secondary"
      }
    ]
  },
  "published": "2026-06-09T17:17:05.437",
  "references": [
    {
      "source": "openssl-security@openssl.org",
      "url": "https://github.com/openssl/openssl/commit/131145d25659e8749a9ed1afb383484854cffb78"
    },
    {
      "source": "openssl-security@openssl.org",
      "url": "https://github.com/openssl/openssl/commit/78d0154cffda03aaaac63a087cc523a6b35fa8fd"
    },
    {
      "source": "openssl-security@openssl.org",
      "url": "https://openssl-library.org/news/secadv/20260609.txt"
    }
  ],
  "sourceIdentifier": "openssl-security@openssl.org",
  "vulnStatus": "Awaiting Analysis",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-415"
        }
      ],
      "source": "openssl-security@openssl.org",
      "type": "Secondary"
    }
  ]
}


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  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
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  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


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