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CVE-2026-69184 (GCVE-0-2026-69184)

Vulnerability from cvelistv5 – Published: 2026-09-18 17:26 – Updated: 2026-09-18 17:26
VLAI
Title
c-ares: CPU-exhaustion denial of service via unbounded DNS name compression pointer chains
Summary
c-ares is an asynchronous resolver library. Prior to 1.34.7, ares_dns_name_parse() enforces backward DNS compression pointers but does not bound the total pointer hops or assembled name length. A malicious DNS server can send a response containing a long descending pointer chain and many resource records whose NAME or RDATA fields refer to the chain, causing repeated decompression work that grows quadratically with message size. A single crafted response can stall the single-threaded c-ares event loop and deny DNS resolution, without causing memory corruption or information disclosure. This issue is fixed in version 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
  • CWE-407 - Inefficient Algorithmic Complexity
Assigner
References
Impacted products
Vendor Product Version CPE status
c-ares c-ares Affected: < 1.34.7
guessed Create a notification for this product.
Show details on NVD website
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{
  "containers": {
    "cna": {
      "affected": [
        {
          "product": "c-ares",
          "vendor": "c-ares",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 1.34.7"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "c-ares is an asynchronous resolver library. Prior to 1.34.7, ares_dns_name_parse() enforces backward DNS compression pointers but does not bound the total pointer hops or assembled name length. A malicious DNS server can send a response containing a long descending pointer chain and many resource records whose NAME or RDATA fields refer to the chain, causing repeated decompression work that grows quadratically with message size. A single crafted response can stall the single-threaded c-ares event loop and deny DNS resolution, without causing memory corruption or information disclosure. This issue is fixed in version 1.34.7."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "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"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-407",
              "description": "CWE-407: Inefficient Algorithmic Complexity",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-09-18T17:26:52.210Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/c-ares/c-ares/security/advisories/GHSA-pjmc-gx33-gc76",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/c-ares/c-ares/security/advisories/GHSA-pjmc-gx33-gc76"
        },
        {
          "name": "https://github.com/c-ares/c-ares/pull/1164",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/c-ares/c-ares/pull/1164"
        },
        {
          "name": "https://github.com/c-ares/c-ares/pull/1210",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/c-ares/c-ares/pull/1210"
        },
        {
          "name": "https://github.com/c-ares/c-ares/commit/5c8341ba6ff3a8e4e4dfd616f8ed0418838b8b7b",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/c-ares/c-ares/commit/5c8341ba6ff3a8e4e4dfd616f8ed0418838b8b7b"
        },
        {
          "name": "https://github.com/c-ares/c-ares/commit/f1288bbc70e9a1e0a77134c2382157e52d326aea",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/c-ares/c-ares/commit/f1288bbc70e9a1e0a77134c2382157e52d326aea"
        },
        {
          "name": "https://github.com/c-ares/c-ares/releases/tag/v1.34.7",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/c-ares/c-ares/releases/tag/v1.34.7"
        }
      ],
      "source": {
        "advisory": "GHSA-pjmc-gx33-gc76",
        "discovery": "UNKNOWN"
      },
      "title": "c-ares: CPU-exhaustion denial of service via unbounded DNS name compression pointer chains"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-69184",
    "datePublished": "2026-09-18T17:26:52.210Z",
    "dateReserved": "2026-08-03T16:00:23.482Z",
    "dateUpdated": "2026-09-18T17:26:52.210Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "nvd": {
      "cve": {
        "affected": [
          {
            "affectedData": [
              {
                "product": "c-ares",
                "vendor": "c-ares",
                "versions": [
                  {
                    "status": "affected",
                    "version": "\u003c 1.34.7"
                  }
                ]
              }
            ],
            "source": "security-advisories@github.com"
          }
        ],
        "cveTags": [],
        "descriptions": [
          {
            "lang": "en",
            "value": "c-ares is an asynchronous resolver library. Prior to 1.34.7, ares_dns_name_parse() enforces backward DNS compression pointers but does not bound the total pointer hops or assembled name length. A malicious DNS server can send a response containing a long descending pointer chain and many resource records whose NAME or RDATA fields refer to the chain, causing repeated decompression work that grows quadratically with message size. A single crafted response can stall the single-threaded c-ares event loop and deny DNS resolution, without causing memory corruption or information disclosure. This issue is fixed in version 1.34.7."
          }
        ],
        "id": "CVE-2026-69184",
        "lastModified": "2026-09-18T18:17:11.477",
        "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"
            }
          ]
        },
        "published": "2026-09-18T18:17:11.477",
        "references": [
          {
            "source": "security-advisories@github.com",
            "url": "https://github.com/c-ares/c-ares/commit/5c8341ba6ff3a8e4e4dfd616f8ed0418838b8b7b"
          },
          {
            "source": "security-advisories@github.com",
            "url": "https://github.com/c-ares/c-ares/commit/f1288bbc70e9a1e0a77134c2382157e52d326aea"
          },
          {
            "source": "security-advisories@github.com",
            "url": "https://github.com/c-ares/c-ares/pull/1164"
          },
          {
            "source": "security-advisories@github.com",
            "url": "https://github.com/c-ares/c-ares/pull/1210"
          },
          {
            "source": "security-advisories@github.com",
            "url": "https://github.com/c-ares/c-ares/releases/tag/v1.34.7"
          },
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            "source": "security-advisories@github.com",
            "url": "https://github.com/c-ares/c-ares/security/advisories/GHSA-pjmc-gx33-gc76"
          }
        ],
        "sourceIdentifier": "security-advisories@github.com",
        "vulnStatus": "Received",
        "weaknesses": [
          {
            "description": [
              {
                "lang": "en",
                "value": "CWE-407"
              }
            ],
            "source": "security-advisories@github.com",
            "type": "Primary"
          }
        ]
      }
    },
    "suse_vex": {
      "aggregate_severity": "important",
      "current_release_date": "2026-09-18T00:29:32Z",
      "cve": "CVE-2026-69184",
      "id": "CVE-2026-69184",
      "initial_release_date": "2026-08-25T01:22:42Z",
      "product_status:known_affected": "430",
      "product_status:recommended": "61",
      "source": "SUSE CSAF VEX",
      "status": "interim",
      "title": "SUSE CVE CVE-2026-69184",
      "url": "https://ftp.suse.com/pub/projects/security/csaf-vex/cve-2026-69184.json",
      "version": "9"
    }
  }
}



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