CVE-2026-34933Public exploit

Local service crash via conflicting D-Bus publish flags

Published Apr 3, 2026 · Updated Apr 3, 2026

Reachable assertion in Avahi before 0.9-rc4 allows local users to crash avahi-daemon through a crafted D-Bus method call. The D-Bus EntryGroup AddRecord and AddService handlers accept simultaneous wide-area and multicast publish flags, which transport_flags_from_domain() treats as a fatal assertion failure. The system-bus policy permits unprivileged local users to reach the handlers; the resulting SIGABRT interrupts mDNS and DNS-SD until the daemon restarts.

CVSS severity5.5
Medium
EPSS probability0.20%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Reachable assertion in Avahi before 0.9-rc4 allows local users to crash avahi-daemon through a crafted D-Bus method call. The D-Bus EntryGroup AddRecord and AddService handlers accept simultaneous wide-area and multicast publish flags, which transport_flags_from_domain() treats as a fatal assertion failure. The system-bus policy permits unprivileged local users to reach the handlers; the resulting SIGABRT interrupts mDNS and DNS-SD until the daemon restarts.

The record

CVE
CVE-2026-34933
Published
Apr 3, 2026
Updated
Apr 3, 2026
Vendor
Avahi
Product
Avahi
Classifications
CWE-617, T1499.004
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Apr 3, 2026CVE publishedPublication date reported by the CVE source.
  2. Apr 3, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 0.9-rc4

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Avahi · Avahiversion=< 0.9-rc4

Published CVSS scores

5.5GitHub, Inc.CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-617Reachable Assertion
T1499.004Application or System Exploitation

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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