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AvahiApplication

CVE-2026-34933

MEDIUM · 5.5 CVSS v3.1 Published 2026-04-03
Fix available
A fix is available. Upgrade to 0.9 or later.
See remediation →
57/100
Remediation priority · Elevated
Public exploit Zero-click Patch available

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
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.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis
How this class of weakness works · CWE-617

Attacker-controllable input can reach an assertion that aborts the process when it fails, so a check meant for debugging becomes a denial-of-service in production. A single crafted request takes the service down. The fix is to handle unexpected input gracefully on reachable paths rather than asserting on it.

General guidance for the reachable assertion class — the official description and references above are authoritative for this specific CVE. Want a bespoke review and a reviewed fix? Ask our team →

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
AvahiApplication
Affected:< 0.9= 0.9

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Local
Complexity
Low
Privileges
Low
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

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

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 0.9 or later
Fixed in 0.9
Vendor patch github.com →
Recommended fix High confidence

Upgrade to Avahi version 0.9-rc4 or later

  1. 1. Check the current installed version of avahi-daemon: dpkg -l | grep avahi or rpm -qa | grep avahi
  2. 2. Update your package manager's package lists: sudo apt-get update (Debian/Ubuntu) or sudo yum check-update (RHEL/CentOS)
  3. 3. Upgrade avahi and avahi-daemon packages to version 0.9-rc4 or later using your package manager: sudo apt-get install avahi-daemon avahi-utils (Debian/Ubuntu) or sudo yum update avahi (RHEL/CentOS)
  4. 4. Verify the installed version after upgrade: avahi-daemon --version
  5. 5. Restart the avahi-daemon service to apply the updated binary: sudo systemctl restart avahi-daemon
  6. 6. Confirm the daemon is running without crashes: sudo systemctl status avahi-daemon
Caveat Minor - this is a bugfix/security release; review release notes for any D-Bus interface changes before upgrading production systems

Generated from the published advisory — verify against the referenced sources before acting.

We can perform the upgrade in your staging environment and verify nothing breaks — typical engagement from $1,600. Get the upgrade done

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-34933 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data