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Fencer Vulns
medium 5.5

CVE-2026-34933 json

Avahi: Reachable assertion in `transport_flags_from_domain()` via conflicting publish flags crashes avahi-daemon

published 2026-04-03 7 mo ago modified 2026-07-24 3 mo ago also EUVD-2026-18910

cvss
5.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 10%
public exploits
0
none known

Summary

Avahi is a system which facilitates service discovery on a local network via the mDNS/DNS-SD protocol suite. Prior to version 0.9-rc4, any unprivileged local user can crash avahi-daemon by sending a single D-Bus method call with conflicting publish flags. This issue has been patched in version 0.9-rc4.

Patch / fix

  • avahi avahi 0.9-rc4
  • avahi Ubuntu 22.04 LTS 0.8-5ubuntu5.5
  • avahi Ubuntu 24.04 LTS 0.8-13ubuntu6.2
  • avahi Ubuntu 25.10 0.8-16ubuntu3.2
  • avahi Ubuntu 26.04 LTS 0.8-18ubuntu1.1
  • avahi Ubuntu Pro 14.04 LTS 0.6.31-4ubuntu1.3+esm5
  • avahi Ubuntu Pro 16.04 LTS 0.6.32~rc+dfsg-1ubuntu2.3+esm5
  • avahi Ubuntu Pro 18.04 LTS 0.7-3.1ubuntu1.3+esm4
  • avahi Ubuntu Pro 20.04 LTS 0.7-4ubuntu7.3+esm2

ubuntu advisories UBUNTU-CVE-2026-34933

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • avahi hummingbird 1 0.9~rc4-0.1.hum1
  • avahi-ui hummingbird 1 0.9~rc4-0.1.hum1
  • avahi-qt3 hummingbird 1 0.9~rc4-0.1.hum1
  • avahi-qt4 hummingbird 1 0.9~rc4-0.1.hum1
  • avahi-qt5 hummingbird 1 0.9~rc4-0.1.hum1
  • avahi-glib hummingbird 1 0.9~rc4-0.1.hum1
  • avahi-libs hummingbird 1 0.9~rc4-0.1.hum1
  • avahi-sharp hummingbird 1 0.9~rc4-0.1.hum1

red hat advisories RHSA-2026:11316

  • avahi SLES 16.0, Linux Micro 6.2, SLES for SAP applications 16.0 0.8-160000.5.1
  • avahi-glib2 SLES for SAP applications 16.0, SLES 16.0 0.8-160000.5.1
  • avahi SLE Micro 5.5, SLE Micro 5.4, SLE Micro 5.3 0.8-150400.7.31.2

suse advisories SUSE-SU-2026:22258-1SUSE-SU-2026:22338-1SUSE-SU-2026:2311-1

  • avahi openSUSE Leap 16.0 0.8-160000.5.1
  • avahi-qt6 openSUSE Leap 16.0 0.8-160000.5.1
  • avahi-glib2 openSUSE Leap 16.0 0.8-160000.5.1
  • avahi openSUSE Tumbleweed 0.8-43.1

opensuse advisories openSUSE-SU-2026:21014-1openSUSE-SU-2026:10670-1

  • avahi Alpine 3.24 0.8-r26

alpine advisories ALPINE-CVE-2026-34933

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • avahi Azure Linux 3.0 0.8-8

azure linux advisories AZL-81959

Azure Linux vulnerability data, Copyright (c) Microsoft Corporation, from https://github.com/microsoft/AzureLinuxVulnerabilityData via OSV, under the MIT licence; changed: normalised to fixed package versions per release. MIT

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-34933 updated cvss 5.5

avahi: avahi-daemon: Avahi: Denial of Service via D-Bus method call

  • Red Hat Enterprise Linux 6 avahi, avahi-ui, avahi-qt3, avahi-qt4, avahi-glib, avahi-libs, +7 more Red Hat Enterprise Linux 7 avahi, avahi-ui, avahi-qt3, avahi-qt4, avahi-glib, avahi-libs, +8 more Red Hat Enterprise Linux 8 avahi, avahi-ui, avahi-glib, avahi-libs, avahi-tools, avahi-autoipd, +5 more Red Hat Enterprise Linux 9 avahi, avahi-glib, avahi-libs, avahi-tools, avahi-autoipd, avahi-gobject, +2 more Red Hat Enterprise Linux 10 avahi Red Hat OpenShift Container Platform 4 openshift/ose-rhel-coreos-8, openshift/ose-rhel-coreos-9
    affected: no fix available “Fix deferred”
  • Red Hat Hardened Images avahi 0.9~rc4-0.1.hum1, avahi-ui 0.9~rc4-0.1.hum1, avahi-qt3 0.9~rc4-0.1.hum1, avahi-qt4 0.9~rc4-0.1.hum1, avahi-qt5 0.9~rc4-0.1.hum1, avahi-glib 0.9~rc4-0.1.hum1, +11 more
    fixed: vendor fix RHSA-2026:11316

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
Proof of concept is public
Automatable
no
Technical impact
partial
Assessed
7 mo ago

Exploit prediction

0.21% chance of exploitation in the next 30 days, higher than 10% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/avahi/avahi/security/advisories/GHSA-w65r-6gxh-vhvc referenced PoC, tagged "exploit" by a source, unverified
  • openwall.com http://www.openwall.com/lists/oss-security/2026/04/11/9 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 5.5 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Affected products

  • avahi avahi

Classification

Weakness

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.