{"id":"CVE-2026-33630","title":"c-ares is an asynchronous resolver library","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 channe…","severity":"high","cvss":7.5,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","cwe":["CWE-415","CWE-416"],"published":"2026-09-03","updated":"2026-09-09","sourceUpdated":"2026-09-09T21:09:13.080","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-33630","references":[{"url":"https://github.com/c-ares/c-ares/commit/1fa3b86a0b8d18fe7b60f3228a01d770feb026bc","label":"security-advisories@github.com"},{"url":"https://github.com/c-ares/c-ares/commit/d823199b688052dcdc1646f2ab4cb8c16b1c644a","label":"security-advisories@github.com"},{"url":"https://github.com/c-ares/c-ares/pull/1237","label":"security-advisories@github.com"},{"url":"https://github.com/c-ares/c-ares/releases/tag/v1.34.7","label":"security-advisories@github.com"},{"url":"https://github.com/c-ares/c-ares/security/advisories/GHSA-6wfj-rwm7-3542","label":"security-advisories@github.com"}],"tags":["nvd"],"epss":0.00452,"epssPercentile":0.38489,"ingestedAt":"2026-09-05T20:44:37.706Z","slug":"CVE-2026-33630","body":"## Overview\n\nc-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.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":41,"depthScoreParts":{"impact":41.3,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}