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AvahiApplication

CVE-2026-24401

MEDIUM · 6.5 CVSS v3.1 Published 2026-01-24
Fix available
A fix is available. Upgrade to 0.9 or later.
See remediation →
72/100
Remediation priority · Elevated
Remotely reachable No privileges 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. 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.

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

A detailed technical summary for this CVE is being prepared.

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
Network
Complexity
Low
Privileges
None
User interaction
Required
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/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 Moderate confidence

Avahi 0.9.1 or later stable release

  1. 1. Check the current Avahi version installed on the system using: dpkg -l | grep avahi or rpm -qa | grep avahi
  2. 2. Upgrade Avahi to the latest available version in your distribution's repositories using: apt-get update && apt-get install avahi-daemon (for Debian/Ubuntu) or yum/dnf update avahi (for RHEL/Fedora)
  3. 3. Verify the new version is installed: avahi-daemon --version
  4. 4. Restart the Avahi daemon to apply the updated package: systemctl restart avahi-daemon (or service avahi-daemon restart)
  5. 5. If the distribution's packages are outdated, download and compile from the official source at https://github.com/avahi/avahi, ensuring to apply or verify commit 78eab31128479f06e30beb8c1cbf99dd921e2524 is included
Caveat Minor - this is a bug fix and security patch; should not break existing functionality

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-2026-24401 in production — separate from our analysis above.

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  • Version or environment caveats, and links to real fixes
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