{"id":"CVE-2026-69186","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-69186","generatedAt":"2026-10-28T00:53:47.888Z","title":"Prior to 1.34.7, ares_dns_parse() trusts the attacker-controlled ANCOUNT, NSCOUNT, and ARCOUNT fields before confirming that the DNS response contains enough bytes for the claimed records.","description":"c-ares is an asynchronous resolver library. Prior to 1.34.7, ares_dns_parse() trusts the attacker-controlled ANCOUNT, NSCOUNT, and ARCOUNT fields before confirming that the DNS response contains enough bytes for the claimed records. Because process_answer() invokes parsing before transaction ID and question validation, a malicious DNS response can cause ares_dns_record_rr_prealloc() and ares_array_set_size() to reserve disproportionate heap memory for a tiny message. Repeated responses create large allocation and release cycles that can degrade or deny name resolution, without causing memory corruption or information disclosure. This issue is fixed in version 1.34.7.","published":"2026-09-18T18:17:12.000Z","lastModified":"2026-09-23T18:12:04.000Z","status":"Awaiting Analysis","sourceIdentifier":"security-advisories@github.com","cvss":{"version":"3.1","score":5.3,"severity":"MEDIUM","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L"},"cwe":["CWE-400"],"affected":[],"epss":{"score":0.00466,"percentile":0.4011,"date":"2026-10-26","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"low","text":"Lower severity and a low EPSS score (0.47%). Track it; it rarely justifies an emergency change on its own."},"changes":[],"references":[{"url":"https://github.com/c-ares/c-ares/commit/e47c203f91cd8b749c8736bc18d75a31ffdec8f4","source":"security-advisories@github.com"},{"url":"https://github.com/c-ares/c-ares/commit/eaded4cb200b2a5f8d73f11021ff7c8d6968aaab","source":"security-advisories@github.com"},{"url":"https://github.com/c-ares/c-ares/pull/1134","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-jv8r-gqr9-68wj","source":"security-advisories@github.com"},{"url":"https://github.com/c-ares/c-ares/security/advisories/GHSA-jv8r-gqr9-68wj","source":"134c704f-9b21-4f2e-91b3-4a467353bcc0"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-69186","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}