CVE-2026-33630
Published:July 06, 2026
Updated:July 07, 2026
Use-after-free / double-free in c-ares query-completion handling. process_timeouts() (and the read_answers() deferred ENDQUERY flush) invoked the query callback without first detaching the query from queries_by_qid/all_queries, so a reentrant ares_cancel() from within the callback frees the query, which the caller then frees again. Remotely triggerable via ares_getaddrinfo() over TCP.
Affected Packages
c-ares (CONAN):
Affected version(s) >=1.33.0 <1.34.7Fix Suggestion:
Update to version 1.34.7https://github.com/c-ares/c-ares.git (GITHUB):
Affected version(s) >=v1.33.0 <v1.34.7Fix Suggestion:
Update to version v1.34.7Related Resources (3)
Do you need more information?
Contact UsCVSS v4
Base Score:
8.7
Attack Vector
NETWORK
Attack Complexity
LOW
Attack Requirements
NONE
Privileges Required
NONE
User Interaction
NONE
Vulnerable System Confidentiality
NONE
Vulnerable System Integrity
NONE
Vulnerable System Availability
HIGH
Subsequent System Confidentiality
NONE
Subsequent System Integrity
NONE
Subsequent System Availability
NONE
CVSS v3
Base Score:
7.5
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH