Affected: AlmaLinux:10: c-ares, AlmaLinux:10: c-ares-devel

The c-ares C library defines asynchronous DNS (Domain Name System) requests and provides name resolving API.

Security Fix(es):

* c-ares: c-ares: Use-after-free / double-free in query-completion handling (CVE-2026-33630)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

Affected: Alpaquita:25: c-ares, Alpaquita:stream: c-ares, BellSoft Hardened Containers:25: c-ares, BellSoft Hardened Containers:stream: c-ares

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.

c-ares-devel-1.34.8-1.1 on GA media

c-ares: c-ares: Use-after-free / double-free in query-completion handling

Affected: Rocky Linux:10: c-ares

The c-ares C library defines asynchronous DNS (Domain Name System) requests and provides name resolving API.

Security Fix(es):

* c-ares: c-ares: Use-after-free / double-free in query-completion handling (CVE-2026-33630)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

Security update for c-ares

Affected: Ubuntu:25.10: c-ares, Ubuntu:26.04:LTS: c-ares

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.

Ein Angreifer kann mehrere Schwachstellen in Red Hat Enterprise Linux ausnutzen, um Administratorrechte zu erlangen, Sicherheitsmaßnahmen zu umgehen, Daten zu manipulieren und einen Denial-of-Service-Zustand auszulösen.