CVE-2026-24401
Avahi has Uncontrolled Recursion in lookup_handle_cname function
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.
INFO
Published Date :
Jan. 24, 2026, 2:15 a.m.
Last Modified :
Feb. 12, 2026, 3:58 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | MEDIUM | [email protected] | ||||
| CVSS 3.1 | MEDIUM | [email protected] |
Solution
- Update avahi-daemon to the patched version.
- Apply the security fix commit 78eab31128479f06e30beb8c1cbf99dd921e2524.
- Restart the avahi-daemon service.
Public PoC/Exploit Available at Github
CVE-2026-24401 has a 1 public
PoC/Exploit available at Github.
Go to the Public Exploits tab to see the list.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-24401.
| URL | Resource |
|---|---|
| https://github.com/avahi/avahi/commit/78eab31128479f06e30beb8c1cbf99dd921e2524 | Patch |
| https://github.com/avahi/avahi/issues/501 | Issue Tracking Patch |
| https://github.com/avahi/avahi/security/advisories/GHSA-h4vp-5m8j-f6w3 | Vendor Advisory |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-24401 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-24401
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Complete mDNS Security Assessment: Tools, Documentation, and Results for 479 hosts
Python
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-24401 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-24401 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
Initial Analysis by [email protected]
Feb. 12, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H Added CPE Configuration OR *cpe:2.3:a:avahi:avahi:*:*:*:*:*:*:*:* versions up to (excluding) 0.9 *cpe:2.3:a:avahi:avahi:0.9:rc1:*:*:*:*:*:* *cpe:2.3:a:avahi:avahi:0.9:rc2:*:*:*:*:*:* Added Reference Type GitHub, Inc.: https://github.com/avahi/avahi/commit/78eab31128479f06e30beb8c1cbf99dd921e2524 Types: Patch Added Reference Type GitHub, Inc.: https://github.com/avahi/avahi/issues/501 Types: Issue Tracking, Patch Added Reference Type GitHub, Inc.: https://github.com/avahi/avahi/security/advisories/GHSA-h4vp-5m8j-f6w3 Types: Vendor Advisory -
New CVE Received by [email protected]
Jan. 24, 2026
Action Type Old Value New Value Added 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. Added CVSS V3.1 AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H Added CWE CWE-674 Added Reference https://github.com/avahi/avahi/commit/78eab31128479f06e30beb8c1cbf99dd921e2524 Added Reference https://github.com/avahi/avahi/issues/501 Added Reference https://github.com/avahi/avahi/security/advisories/GHSA-h4vp-5m8j-f6w3