CVE-2026-24401

MEDIUM
MEDIUM Priority: 0.02 BB Relevance: 63/100
Published: 2026-01-24 Modified: 2026-10-23 First seen: 2026-10-29 Status: active

Attack Surface

Network Low Complexity No Auth

CVSS Vector Breakdown

AV: Network
AC: Low
PR: None
UI: Required
S: Unchanged
C: None
I: None
A: High

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.

Weakness Classification (1)

Affected Software (3)

VendorProductVersion
avahi avahi < 0.9
avahi avahi 0.9
avahi avahi 0.9

Bug Bounty Relevance

63 / 100
✓ Network accessible
✓ No authentication
✓ Low complexity

CVSS Score

6.5 / 10.0 v3.1
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H

EPSS — Exploitation Probability

0.37%
Raw Score 0.003730
Percentile 31.2%
Date 2026-10-29

EPSS Trend

2026-10-29
0.00373
2026-10-28
0.00373

Intelligence Sources

nvd ref →