{"id":"CVE-2026-33630","summary":"c-ares : Use-after-free / double-free in c-ares query-completion handling, remotely triggerable via ares_getaddrinfo() over TCP","details":"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.","aliases":["GHSA-6wfj-rwm7-3542"],"modified":"2026-09-04T11:45:58.672325582Z","published":"2026-09-03T18:42:28.783Z","related":["ALSA-2026:42096","openSUSE-SU-2026:11593-1","openSUSE-SU-2026:21721-1"],"database_specific":{"cna_assigner":"GitHub_M","cwe_ids":["CWE-415","CWE-416"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/33xxx/CVE-2026-33630.json"},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/33xxx/CVE-2026-33630.json"},{"type":"FIX","url":"https://github.com/c-ares/c-ares/commit/1fa3b86a0b8d18fe7b60f3228a01d770feb026bc"},{"type":"FIX","url":"https://github.com/c-ares/c-ares/commit/d823199b688052dcdc1646f2ab4cb8c16b1c644a"},{"type":"FIX","url":"https://github.com/c-ares/c-ares/pull/1237"},{"type":"WEB","url":"https://github.com/c-ares/c-ares/releases/tag/v1.34.7"},{"type":"ADVISORY","url":"https://github.com/c-ares/c-ares/security/advisories/GHSA-6wfj-rwm7-3542"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-33630"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/c-ares/c-ares","events":[{"introduced":"5899dea2b1f8e78f311aaed7db98b82b5537c9f9"},{"fixed":"d63b7de3a3568d14ab1351374b205365aed51cca"}],"database_specific":{"source":"AFFECTED_FIELD","extracted_events":[{"introduced":"1.32.3"},{"fixed":"1.34.7"}]}}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-33630.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"}]}