{"id":"CVE-2026-69184","state":"PUBLISHED","title":"c-ares: CPU-exhaustion denial of service via unbounded DNS name compression pointer chains","description":"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.","publishedAt":"2026-09-18T17:26:52.210Z","updatedAt":"2026-09-21T20:48:59.663Z","severity":{"score":7.5,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","source":"GitHub_M"},"assigner":"GitHub_M","products":["c-ares c-ares"],"affected":[{"vendor":"c-ares","product":"c-ares","versions":[{"version":"< 1.34.7","status":"affected"}]}],"references":["https://github.com/c-ares/c-ares/security/advisories/GHSA-pjmc-gx33-gc76","https://github.com/c-ares/c-ares/pull/1164","https://github.com/c-ares/c-ares/pull/1210","https://github.com/c-ares/c-ares/commit/5c8341ba6ff3a8e4e4dfd616f8ed0418838b8b7b","https://github.com/c-ares/c-ares/commit/f1288bbc70e9a1e0a77134c2382157e52d326aea","https://github.com/c-ares/c-ares/releases/tag/v1.34.7"],"weaknesses":["CWE-407"],"ingestedAt":"2026-10-29T20:12:49.727Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/69xxx/CVE-2026-69184.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-69184","state":"PUBLISHED","datePublished":"2026-09-18T17:26:52.210Z","dateUpdated":"2026-09-21T20:48:59.663Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-08-03T16:00:23.482Z"},"containers":{"cna":{"title":"c-ares: CPU-exhaustion denial of service via unbounded DNS name compression pointer chains","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."}],"affected":[{"vendor":"c-ares","product":"c-ares","versions":[{"version":"< 1.34.7","status":"affected"}]}],"references":[{"url":"https://github.com/c-ares/c-ares/security/advisories/GHSA-pjmc-gx33-gc76","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/pull/1164","name":"https://github.com/c-ares/c-ares/pull/1164","tags":["x_refsource_MISC"]},{"url":"https://github.com/c-ares/c-ares/pull/1210","name":"https://github.com/c-ares/c-ares/pull/1210","tags":["x_refsource_MISC"]},{"url":"https://github.com/c-ares/c-ares/commit/5c8341ba6ff3a8e4e4dfd616f8ed0418838b8b7b","name":"https://github.com/c-ares/c-ares/commit/5c8341ba6ff3a8e4e4dfd616f8ed0418838b8b7b","tags":["x_refsource_MISC"]},{"url":"https://github.com/c-ares/c-ares/commit/f1288bbc70e9a1e0a77134c2382157e52d326aea","name":"https://github.com/c-ares/c-ares/commit/f1288bbc70e9a1e0a77134c2382157e52d326aea","tags":["x_refsource_MISC"]},{"url":"https://github.com/c-ares/c-ares/releases/tag/v1.34.7","name":"https://github.com/c-ares/c-ares/releases/tag/v1.34.7","tags":["x_refsource_MISC"]}],"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","lang":"en","description":"CWE-407: Inefficient Algorithmic Complexity","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-09-18T17:26:52.210Z"},"source":{"advisory":"GHSA-pjmc-gx33-gc76","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-09-18T20:13:18.897117Z","id":"CVE-2026-69184","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-09-21T20:48:59.663Z"}}]}}}