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FKIE_CVE-2026-33630

Vulnerability from fkie_nvd - Published: 2026-09-03 19:17 - Updated: 2026-09-05 03:17
Severity
7.5 (High) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Summary
c-ares is an asynchronous resolver library. From ver 1.32.3 until 1.34.7, a use-after-free / double-free in c-ares' query-completion handling. The same flaw — a query's callback being invoked while the query is still linked in the channel's internal lookup structures — is present at multiple points in the resend/finish path (timeout handling, response handling, and query dispatch). If the query, or for ares_getaddrinfo() the owning host_query, is freed as a side effect of that callback, it is then accessed and/or freed a second time. This vulnerability is fixed in ver 1.34.7.
References
security-advisories@github.comhttps://github.com/c-ares/c-ares/commit/1fa3b86a0b8d18fe7b60f3228a01d770feb026bc
security-advisories@github.comhttps://github.com/c-ares/c-ares/commit/d823199b688052dcdc1646f2ab4cb8c16b1c644a
security-advisories@github.comhttps://github.com/c-ares/c-ares/pull/1237
security-advisories@github.comhttps://github.com/c-ares/c-ares/releases/tag/v1.34.7
security-advisories@github.comhttps://github.com/c-ares/c-ares/security/advisories/GHSA-6wfj-rwm7-3542
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "product": "c-ares",
          "vendor": "c-ares",
          "versions": [
            {
              "status": "affected",
              "version": "\u003e= 1.32.3, \u003c 1.34.7"
            }
          ]
        }
      ],
      "source": "security-advisories@github.com"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "c-ares is an asynchronous resolver library. From ver 1.32.3 until 1.34.7, a use-after-free / double-free in c-ares\u0027 query-completion handling. The same flaw \u2014 a query\u0027s callback being invoked while the query is still linked in the channel\u0027s internal lookup structures \u2014 is present at multiple points in the resend/finish path (timeout handling, response handling, and query dispatch). If the query, or for ares_getaddrinfo() the owning host_query, is freed as a side effect of that callback, it is then accessed and/or freed a second time. This vulnerability is fixed in ver 1.34.7."
    }
  ],
  "id": "CVE-2026-33630",
  "lastModified": "2026-09-05T03:17:15.290",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "HIGH",
          "baseScore": 7.5,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 3.6,
        "source": "security-advisories@github.com",
        "type": "Secondary"
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-33630",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "yes"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "timestamp": "2026-09-05T02:00:43.010024Z",
          "version": "2.0.3"
        }
      }
    ]
  },
  "published": "2026-09-03T19:17:27.420",
  "references": [
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/c-ares/c-ares/commit/1fa3b86a0b8d18fe7b60f3228a01d770feb026bc"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/c-ares/c-ares/commit/d823199b688052dcdc1646f2ab4cb8c16b1c644a"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/c-ares/c-ares/pull/1237"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/c-ares/c-ares/releases/tag/v1.34.7"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/c-ares/c-ares/security/advisories/GHSA-6wfj-rwm7-3542"
    }
  ],
  "sourceIdentifier": "security-advisories@github.com",
  "vulnStatus": "Received",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-415"
        },
        {
          "lang": "en",
          "value": "CWE-416"
        }
      ],
      "source": "security-advisories@github.com",
      "type": "Secondary"
    }
  ]
}



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