Vulnerability Description
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.
CVSS Score
MEDIUM
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Avahi | Avahi | < 0.9 |
Related Weaknesses (CWE)
References
- https://github.com/avahi/avahi/commit/78eab31128479f06e30beb8c1cbf99dd921e2524Patch
- https://github.com/avahi/avahi/issues/501Issue TrackingPatch
- https://github.com/avahi/avahi/security/advisories/GHSA-h4vp-5m8j-f6w3Vendor Advisory
FAQ
What is CVE-2026-24401?
CVE-2026-24401 is a vulnerability with a CVSS score of 6.5 (MEDIUM). 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 sendi...
How severe is CVE-2026-24401?
CVE-2026-24401 has been rated MEDIUM with a CVSS base score of 6.5/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-24401?
Check the references section above for vendor advisories and patch information. Affected products include: Avahi Avahi.