CVE-2026-24401

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.

Database specific

{
    "cna_assigner":  "GitHub_M",
    "cwe_ids":  [
        "CWE-674"
    ],
    "osv_generated_from":  "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/24xxx/CVE-2026-24401.json",
    "unresolved_ranges":  [
        {
            "extracted_events":  [
                {
                    "fixed":  "78eab31128479f06e30beb8c1cbf99dd921e2524"
                }
            ],
            "source":  "AFFECTED_FIELD"
        }
    ]
}

References

Affected packages

Git / github.com/avahi/avahi

Affected ranges

Type

GIT

Repo

https://github.com/avahi/avahi

Events

Introduced

8ee3bd6f7921b489bde14f120187a5becf134d30

Fixed

78eab31128479f06e30beb8c1cbf99dd921e2524

Database specific

Show details

{
    "cpe":  [
        "cpe:2.3:a:avahi:avahi:0.9:rc1:*:*:*:*:*:*",
        "cpe:2.3:a:avahi:avahi:0.9:rc2:*:*:*:*:*:*"
    ],
    "extracted_events":  [
        {
            "introduced":  "0.9-rc1"
        },
        {
            "last_affected":  "0.9-rc1"
        },
        {
            "introduced":  "0.9-rc2"
        },
        {
            "last_affected":  "0.9-rc2"
        }
    ],
    "source":  [
        "CPE_STRING",
        "REFERENCES"
    ]
}

Affected versions

0.*

0.9-rc1

0.9-rc2

v0.*

v0.9-rc1

v0.9-rc2

Database specific

source

"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-24401.json"

vanir_signatures

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    {
        "deprecated":  false,
        "digest":  {
            "function_hash":  "332737092712039648650165003545039931030",
            "length":  724
        },
        "id":  "CVE-2026-24401-173bd870",
        "signature_type":  "Function",
        "signature_version":  "v1",
        "source":  "https://github.com/avahi/avahi/commit/78eab31128479f06e30beb8c1cbf99dd921e2524",
        "target":  {
            "file":  "avahi-core/browse.c",
            "function":  "lookup_handle_cname"
        }
    },
    {
        "deprecated":  false,
        "digest":  {
            "line_hashes":  [
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            ],
            "threshold":  0.9
        },
        "id":  "CVE-2026-24401-2058ab72",
        "signature_type":  "Line",
        "signature_version":  "v1",
        "source":  "https://github.com/avahi/avahi/commit/78eab31128479f06e30beb8c1cbf99dd921e2524",
        "target":  {
            "file":  "avahi-core/browse.c"
        }
    }
]

vanir_signatures_modified

"2026-08-19T15:11:41Z"