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CVE-2026-33630 (GCVE-0-2026-33630)

Vulnerability from cvelistv5 – Published: 2026-09-03 18:42 – Updated: 2026-09-03 20:04
VLAI
Title
c-ares : Use-after-free / double-free in c-ares query-completion handling, remotely triggerable via ares_getaddrinfo() over TCP
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.
Severity
7.5 (High)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CWE
Assigner
References
Impacted products
Vendor Product Version CPE status
c-ares c-ares Affected: >= 1.32.3, < 1.34.7
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{
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        {
          "product": "c-ares",
          "vendor": "c-ares",
          "versions": [
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        }
      ],
      "metrics": [
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            "baseSeverity": "HIGH",
            "confidentialityImpact": "NONE",
            "integrityImpact": "NONE",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
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        },
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        }
      ],
      "source": {
        "advisory": "GHSA-6wfj-rwm7-3542",
        "discovery": "UNKNOWN"
      },
      "title": "c-ares : Use-after-free / double-free in c-ares query-completion handling, remotely triggerable via ares_getaddrinfo() over TCP"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-33630",
    "datePublished": "2026-09-03T18:42:28.783Z",
    "dateReserved": "2026-03-23T14:24:11.618Z",
    "dateUpdated": "2026-09-03T20:04:36.574Z",
    "state": "PUBLISHED"
  },
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  "vulnerability-lookup:meta": {
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      "cve": "CVE-2026-33630",
      "id": "CVE-2026-33630",
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      "source": "Red Hat CSAF VEX",
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      "title": "c-ares: c-ares: Use-after-free / double-free in query-completion handling",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-33630.json",
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      "cve": "CVE-2026-33630",
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      "title": "SUSE CVE CVE-2026-33630",
      "url": "https://ftp.suse.com/pub/projects/security/csaf-vex/cve-2026-33630.json",
      "version": "6"
    }
  }
}



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Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

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.