CVE-2026-24401

Avahi has Uncontrolled Recursion in lookup_handle_cname function

MEDIUM
6.5
CVSS Score
Published: January 24, 2026 at 01:25 AM UTC
Updated: October 23, 2026 at 04:16 PM UTC
1 product affected across 1 vendorAvahi

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Severity
MEDIUM6.5
Exploit prediction
EPSS 0.4%
SSVC
No known exploit

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

References (3)

x_refsource_CONFIRMVendor Advisory
Source: cverecord
https://github.com/avahi/avahi/security/advisories/GHSA-h4vp-5m8j-f6w3
x_refsource_MISCIssue TrackingPatch
Source: cverecord
https://github.com/avahi/avahi/issues/501

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

6.5MEDIUMGitHub_M
Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
REQUIRED
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-674

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