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Vulnerabilities

Security fix · CVE-2025-59529

Avahi is a system which facilitates service discovery on a local network via the mDNS/DNS-SD protocol suite.

Published Dec 18, 2025 · catalog updated Oct 23, 2026 · Avahi is a system

Open the advisory

Exploitation likelihood is not on this record for CVE-2025-59529. A missing EPSS score is not a low risk. Compare Avahi is a system with the linked advisory before you change production.

Gaps on this record

  • The stored product name is a package slug. The name on this page is taken from the title (Avahi is a system).
  • No vendor fix or required action is stored. Compare the linked advisory before you change production.
  • EPSS is missing. A missing score is not a low risk.
Severity
Medium5.5
Known exploitation
Not in CISA/VulnCheck KEV
EPSS
Not in the current FIRST EPSS dataset
Remediation
Version ranges on file
Affected products
cpe avahi/avahi

Avahi is a system which facilitates service discovery on a local network via the mDNS/DNS-SD protocol suite. In versions up to and including 0.9-rc2, the simple protocol server ignores the documented client limit and accepts unlimited connections, allowing for easy local DoS. Although is defined, unconditionally s and always appends the new client and increments . There is no check against the limit. When client cannot be accepted as a result of maximal socket number of avahi-daemon, it logs unconditionally error per each connection. Unprivileged local users can exhaust daemon memory and file descriptors, causing a denial of service system-wide for mDNS/DNS-SD. Exhausting local file descriptors causes increased system load caused by logging errors of each of request. Overloading prevents glibc calls using nss-mdns plugins to resolve names and link-local addresses. As of time of publication, no known patched versions are available, but a candidate fix is available in pull request 808, and some workarounds are available. Simple clients are offered for nss-mdns package functionality. It is not possible to disable the unix socket , but resolution requests received via DBus are not affected directly. Tools avahi-resolve, avahi-resolve-address and avahi-resolve-host-name are not affected, they use DBus interface. It is possible to change permissions of unix socket after avahi-daemon is started. But avahi-daemon does not provide any configuration for it. Additional access restrictions like SELinux can also prevent unwanted tools to access the socket and keep resolution working for trusted users.

Are you affected?

Enter the version you run. The result uses only the ranges stored on this record.

The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.

  • cpe avahi/avahi0.9
  • cpe avahi/avahi< 0.9

How to fix CVE-2025-59529

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

Exploitation likelihood is not on this record for CVE-2025-59529. A missing EPSS score is not a low risk. Compare Avahi is a system with the linked advisory before you change production.

Which versions are affected?

Compare what you have installed with 0.9, < 0.9. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

CWE-400: Uncontrolled Resource Consumption. EPSS is absent from the current FIRST dataset. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Code

The project this record applies to. Exploit listings stay in References.

Timeline

Detection, updates, and resolution for this record.

  1. Dec 18, 2025 · NIST NVD

    Detected

    Avahi is a system which facilitates service discovery on a local network via the mDNS/DNS-SD protocol suite. In versions up to and including 0.9-rc2, the simple protocol server ignores the documented client limit and accepts unlimited connections, allowing for easy local DoS. Although is defined, unconditionally s and always appends the new client and increments . There is no check against the lim

  2. Oct 23, 2026 · NIST NVD

    Updated

    Avahi is a system which facilitates service discovery on a local network via the mDNS/DNS-SD protocol suite. In versions up to and including 0.9-rc2, the simple protocol server ignores the documented client limit and accepts unlimited connections, allowing for easy local DoS. Although is defined, unconditionally s and always appends the new client and increments . There is no check against the lim

Sources

  • CVE.orgVulnerability recordCVE-2025-59529

    Official CVE identifier

    cve.org
  • NIST NVDVulnerability recordCVE-2025-59529

    Avahi is a system which facilitates service discovery on a local network via the mDNS/DNS-SD protocol suite. In versions up to and including 0.9-rc2, the simple protocol server ignores the documented client limit and accepts unlimited connections, allowing for easy local DoS. Alt

    nvd.nist.gov

References

Freshness

Last verified in this catalog Oct 23, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.