CVE-2026-24401Avahi has Uncontrolled Recursion in lookup_handle_cname function

Beschreibung

Avahi is a system which facilitates service discovery on a local network via the mDNS/DNS-SD protocol suite. In versions 0.9rc2 and below, avahi-daemon can be crashed via a segmentation fault by sending an unsolicited mDNS response containing a recursive CNAME record, where the alias and canonical name point to the same domain (e.g., "h.local" as a CNAME for "h.local"). This causes unbounded recursion in the lookup_handle_cname function, leading to stack exhaustion. The vulnerability affects record browsers where AVAHI_LOOKUP_USE_MULTICAST is set explicitly, which includes record browsers created by resolvers used by nss-mdns. This issue is patched in commit 78eab31128479f06e30beb8c1cbf99dd921e2524, which is part of version 0.9-rc3.

Daten: CVE.org, NVD, CISA KEV, FIRST EPSS, Ubuntu. Wiedergegeben wie in der Quelle, auf Englisch.

Betroffene Produkte und Versionen

Referenzen und Patches

• https://github.com/avahi/avahi/security/advisories/GHSA-h4vp-5m8j-f6w3 Vendor Advisory
• https://github.com/avahi/avahi/issues/501 Issue TrackingPatch
• https://github.com/avahi/avahi/commit/78eab31128479f06e30beb8c1cbf99dd921e2524 Patch