{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "versions": [
              {
                "introduced": "0"
              },
              {
                "last_affected": "0.9-rc2"
              }
            ]
          },
          "events": [
            {
              "introduced": "0"
            },
            {
              "last_affected": "1dade81cbf4d3e3f49784e44e543cd77046c79df"
            }
          ],
          "repo": "https://github.com/avahi/avahi",
          "type": "GIT"
        }
      ]
    },
    {
      "ranges": [
        {
          "database_specific": {
            "versions": [
              {
                "introduced": "0"
              },
              {
                "last_affected": "0.9-rc1"
              }
            ]
          },
          "events": [
            {
              "introduced": "0"
            },
            {
              "last_affected": "8ee3bd6f7921b489bde14f120187a5becf134d30"
            }
          ],
          "repo": "https://github.com/lathiat/avahi",
          "type": "GIT"
        }
      ]
    }
  ],
  "aliases": [
    "GHSA-73wf-3xmj-x82q"
  ],
  "database_specific": {
    "cna_assigner": "GitHub_M",
    "cwe_ids": [
      "CWE-400"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/59xxx/CVE-2025-59529.json"
  },
  "details": "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 `CLIENTS_MAX` is defined, `server_work()` unconditionally `accept()`s and `client_new()` always appends the new client and increments `n_clients`. 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 `*.local.` 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 `/run/avahi-daemon/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.",
  "id": "CVE-2025-59529",
  "modified": "2026-04-01T23:08:38.030816530Z",
  "published": "2025-12-18T20:25:31.499Z",
  "references": [
    {
      "type": "WEB",
      "url": "http://www.openwall.com/lists/oss-security/2025/12/19/1"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/59xxx/CVE-2025-59529.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/avahi/avahi/security/advisories/GHSA-73wf-3xmj-x82q"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2025-59529"
    },
    {
      "type": "FIX",
      "url": "https://github.com/avahi/avahi/pull/808"
    },
    {
      "type": "ARTICLE",
      "url": "https://zeropath.com/blog/avahi-simple-protocol-server-dos-cve-2025-59529"
    }
  ],
  "schema_version": "1.7.3",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "simple protocol server ignores accepts unlimited connections and logs failures without limit"
}