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NVD / CVE Program· CNA GitHub_M

CVE-2026-24401: Avahi has Uncontrolled Recursion in lookup_handle_cname function

Noroxi assessment

Priority: Monitor (action score 26/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.37% (FIRST EPSS).
  • Anyone who can reach it over the internet can trigger it. No account or password is required. A user must open a link or visit a page. No special conditions are required; it is repeatable.
  • Fixed version: avahi (Alpine:v3.24) 0.8-r25; avahi (Debian:14) 0.8-18; avahi (openSUSE:Leap 15.6) 0.8-150600.15.15.1.

Low priority for now. Upgrade to avahi (Alpine:v3.24) 0.8-r25; avahi (Debian:14) 0.8-18; avahi (openSUSE:Leap 15.6) 0.8-150600.15.15.1 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

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.

MediumCVSS 6.5 · v3.1—No exploit Fix available
Published
Jan 24, 2026
Updated
Oct 23, 2026
EPSS
0.3% · 30th percentile

Report tools

JSON

Action score

26

Monitor

Low priority for now.

CVSS
26 / 40 · 6.5 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.3%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
6.5
CNA · GitHub_M
6.5
agree

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2026-24401

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
avahiavahi

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • avahi avahibefore 0.9
  • avahi avahi0.9

Versions reported by the vendor

Affected version ranges reported by the assigning authority (GitHub_M). Independent of NVD's CPE analysis and usually ahead of it.

  • avahi avahi

    • < 0.9-rc3affected

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Alpine:v3.24avahibefore 0.8-r250.8-r25
Debian:12avahifrom 0—
Debian:14avahibefore 0.8-180.8-18
openSUSE:Leap 15.6avahibefore 0.8-150600.15.15.10.8-150600.15.15.1
openSUSE:Leap 15.6avahi-glib2before 0.8-150600.15.15.10.8-150600.15.15.1
openSUSE:Leap 15.6avahi-qt5before 0.8-150600.15.15.10.8-150600.15.15.1
openSUSE:Leap 16.0avahibefore 0.8-160000.5.10.8-160000.5.1
openSUSE:Leap 16.0avahi-glib2before 0.8-160000.5.10.8-160000.5.1
openSUSE:Leap 16.0avahi-qt6before 0.8-160000.5.10.8-160000.5.1
openSUSE:Tumbleweedavahibefore 0.8-44.10.8-44.1
Red Hat:hummingbird:1avahibefore 0:0.9~rc4-0.1.hum10:0.9~rc4-0.1.hum1
Red Hat:hummingbird:1avahi-autoipdbefore 0:0.9~rc4-0.1.hum10:0.9~rc4-0.1.hum1
Red Hat:hummingbird:1avahi-compat-howlbefore 0:0.9~rc4-0.1.hum10:0.9~rc4-0.1.hum1
Red Hat:hummingbird:1avahi-compat-howl-develbefore 0:0.9~rc4-0.1.hum10:0.9~rc4-0.1.hum1
Red Hat:hummingbird:1avahi-compat-libdns_sdbefore 0:0.9~rc4-0.1.hum10:0.9~rc4-0.1.hum1
Red Hat:hummingbird:1avahi-compat-libdns_sd-develbefore 0:0.9~rc4-0.1.hum10:0.9~rc4-0.1.hum1
Red Hat:hummingbird:1avahi-develbefore 0:0.9~rc4-0.1.hum10:0.9~rc4-0.1.hum1
Red Hat:hummingbird:1avahi-dnsconfdbefore 0:0.9~rc4-0.1.hum10:0.9~rc4-0.1.hum1
Red Hat:hummingbird:1avahi-glibbefore 0:0.9~rc4-0.1.hum10:0.9~rc4-0.1.hum1
Red Hat:hummingbird:1avahi-glib-develbefore 0:0.9~rc4-0.1.hum10:0.9~rc4-0.1.hum1
Red Hat:hummingbird:1avahi-gobjectbefore 0:0.9~rc4-0.1.hum10:0.9~rc4-0.1.hum1
Red Hat:hummingbird:1avahi-gobject-develbefore 0:0.9~rc4-0.1.hum10:0.9~rc4-0.1.hum1
Red Hat:hummingbird:1avahi-libsbefore 0:0.9~rc4-0.1.hum10:0.9~rc4-0.1.hum1
Red Hat:hummingbird:1avahi-qt3before 0:0.9~rc4-0.1.hum10:0.9~rc4-0.1.hum1

+22

Same product

avahi: all records

Other highest-scoring records for the same primary product.

  • CVE-2008-5081The originates_from_local_legacy_unicast_socket function (avahi-core/server.c) in avahi-daemon in Avahi before 0.6.24 allows remote attacker
    40Plan
  • CVE-2017-6519avahi-daemon in Avahi through 0.6.32 and 0.7 inadvertently responds to IPv6 unicast queries with source addresses that are not on-link, whic
    37Monitor
  • CVE-2021-26720avahi-daemon-check-dns.sh in the Debian avahi package through 0.8-4 is executed as root via /etc/network/if-up.d/avahi-daemon, and allows a
    31Monitor

Published before and after this one in the same product

  • ← EarlierCVE-2025-68468Jan 12, 2026 · Avahi has a reachable assertion in lookup_multicast_callback
    26Monitor
  • ← EarlierCVE-2025-68471Jan 12, 2026 · Avahi has a reachable assertion in lookup_start
    26Monitor
  • Later →CVE-2026-34933Apr 3, 2026 · Avahi: Reachable assertion in `transport_flags_from_domain()` via conflicting publish flags crashes avahi-daemon
    22Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
alpine:avahi0.8-r25 · Alpine:v3.24Package registry (OSV)
debian:avahi0.8-18 · Debian:14Package registry (OSV)
opensuse:avahi0.8-150600.15.15.1 · openSUSE:Leap 15.6Package registry (OSV)
opensuse:avahi-glib20.8-150600.15.15.1 · openSUSE:Leap 15.6Package registry (OSV)
opensuse:avahi-qt50.8-150600.15.15.1 · openSUSE:Leap 15.6Package registry (OSV)
opensuse:avahi-qt60.8-160000.5.1 · openSUSE:Leap 16.0Package registry (OSV)
red hat:avahi0:0.9~rc4-0.1.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:avahi-autoipd0:0.9~rc4-0.1.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:avahi-compat-howl0:0.9~rc4-0.1.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:avahi-compat-howl-devel0:0.9~rc4-0.1.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:avahi-compat-libdns_sd0:0.9~rc4-0.1.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:avahi-compat-libdns_sd-devel0:0.9~rc4-0.1.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:avahi-devel0:0.9~rc4-0.1.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:avahi-dnsconfd0:0.9~rc4-0.1.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:avahi-glib0:0.9~rc4-0.1.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:avahi-glib-devel0:0.9~rc4-0.1.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:avahi-gobject0:0.9~rc4-0.1.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:avahi-gobject-devel0:0.9~rc4-0.1.hum1 · Red Hat:hummingbird:1Package registry (OSV)
suse:avahi0.7-150100.3.49.1 · SUSE:Linux Enterprise Micro 5.2Package registry (OSV)
suse:avahi0.8-150600.15.15.1 · SUSE:Linux Enterprise Module for Basesystem 15 SP7Package registry (OSV)
suse:avahi-glib20.8-150600.15.15.1 · SUSE:Linux Enterprise Module for Basesystem 15 SP7Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • No account or password is required.
  • A user must open a link or visit a page.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
none
Integrity
none
Availability
high · the service can be disrupted
Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
Required
Scope
Unchanged
Confidentiality impact
None
Integrity impact
None
Availability impact
High

Weakness class (CWE)

CWE-674 · Uncontrolled Recursion

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H

nvd-primary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

ATT&CK techniques

—

Change log

  1. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (2 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records