CVE-2026-24401

Avahi has Uncontrolled Recursion in lookup_handle_cname function

State
Published
Severity
6.5 Medium
Published
Jan 24, 2026
Updated
Oct 23, 2026
Reserved
Jan 22, 2026

Read the record on cve.org

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, which is part of version 0.9-rc3.

Scores

CVSSScoreVectorSource
3.16.5 MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:HGitHub_M

Weaknesses

Affected Products

ProductVersions
avahiavahi
  • < 0.9-rc3Affected

References

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