CVE-2026-24401

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{"affected": [{"affectedData": [{"product": "avahi", "vendor": "avahi", "versions": [{"status": "affected", "version": "< 0.9-rc3"}]}], "source": "security-advisories@github.com"}], "configurations": [{"nodes": [{"cpeMatch": [{"criteria": "cpe:2.3:a:avahi:avahi:*:*:*:*:*:*:*:*", "matchCriteriaId": "6481267F-934F-4A0C-9B25-59738E798458", "versionEndExcluding": "0.9", "vulnerable": true}, {"criteria": "cpe:2.3:a:avahi:avahi:0.9:rc1:*:*:*:*:*:*", "matchCriteriaId": "76971590-AEED-4CB1-B7B7-45EA8FD11524", "vulnerable": true}, {"criteria": "cpe:2.3:a:avahi:avahi:0.9:rc2:*:*:*:*:*:*", "matchCriteriaId": "83D94AE4-46AC-4955-BB0D-193CF79149A1", "vulnerable": true}], "negate": false, "operator": "OR"}]}], "cveTags": [], "descriptions": [{"lang": "en", "value": "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, which is part of version 0.9-rc3."}, {"lang": "es", "value": "Avahi es un sistema que facilita el descubrimiento de servicios en una red local a trav\u00e9s de la suite de protocolos mDNS/DNS-SD. En las versiones 0.9rc2 e inferiores, avahi-daemon puede ser bloqueado mediante un fallo de segmentaci\u00f3n al enviar una respuesta mDNS no solicitada que contenga un registro CNAME recursivo, donde el alias y el nombre can\u00f3nico apuntan al mismo dominio (por ejemplo, 'h.local' como CNAME para 'h.local'). Esto causa una recursi\u00f3n ilimitada en la funci\u00f3n lookup_handle_cname, lo que lleva al agotamiento de la pila. La vulnerabilidad afecta a los navegadores de registros donde AVAHI_LOOKUP_USE_MULTICAST est\u00e1 configurado expl\u00edcitamente, lo que incluye los navegadores de registros creados por los resolvedores utilizados por nss-mdns. Este problema est\u00e1 parcheado en el commit 78eab31128479f06e30beb8c1cbf99dd921e2524."}], "id": "CVE-2026-24401", "lastModified": "2026-10-23T16:16:51.507", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 6.5, "baseSeverity": "MEDIUM", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "REQUIRED", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H", "version": "3.1"}, "exploitabilityScore": 2.8, "impactScore": 3.6, "source": "security-advisories@github.com", "type": "Secondary"}, {"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 6.5, "baseSeverity": "MEDIUM", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "REQUIRED", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H", "version": "3.1"}, "exploitabilityScore": 2.8, "impactScore": 3.6, "source": "nvd@nist.gov", "type": "Primary"}], "ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-24401", "options": [{"exploitation": "none"}, {"automatable": "no"}, {"technicalImpact": "partial"}], "role": "CISA Coordinator", "timestamp": "2026-01-26T16:14:24.982686Z", "version": "2.0.3"}}]}, "published": "2026-01-24T02:15:48.760", "references": [{"source": "security-advisories@github.com", "tags": ["Patch"], "url": "https://github.com/avahi/avahi/commit/78eab31128479f06e30beb8c1cbf99dd921e2524"}, {"source": "security-advisories@github.com", "tags": ["Issue Tracking", "Patch"], "url": "https://github.com/avahi/avahi/issues/501"}, {"source": "security-advisories@github.com", "tags": ["Vendor Advisory"], "url": "https://github.com/avahi/avahi/security/advisories/GHSA-h4vp-5m8j-f6w3"}], "sourceIdentifier": "security-advisories@github.com", "vulnStatus": "Modified", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-674"}], "source": "security-advisories@github.com", "type": "Secondary"}]}

{"bugzilla": {"description": "avahi: Avahi: Denial of Service via recursive CNAME record in mDNS response", "id": "2432534", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2432534"}, "csaw": false, "cvss3": {"cvss3_base_score": "6.5", "cvss3_scoring_vector": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H", "status": "draft"}, "cwe": "CWE-674", "details": ["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.", "A flaw was found in Avahi, a system that enables devices to discover services on a local network. A remote attacker can exploit this vulnerability by sending a specially crafted mDNS (multicast Domain Name System) response containing a recursive CNAME (Canonical Name) record. This triggers an uncontrolled recursion within the avahi-daemon process, leading to stack exhaustion and causing the service to crash. This results in a denial of service (DoS) for affected systems."], "mitigation": {"lang": "en:us", "value": "To mitigate this issue, disable the avahi-daemon service if mDNS/DNS-SD functionality is not required on the system.\n```bash\nsudo systemctl disable --now avahi-daemon.service\nsudo systemctl mask avahi-daemon.service\n```\nDisabling this service may impact applications relying on mDNS for local network service discovery. A system reboot or service reload may be required for the changes to take full effect."}, "name": "CVE-2026-24401", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Fix deferred", "package_name": "avahi", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:6", "fix_state": "Fix deferred", "package_name": "avahi", "product_name": "Red Hat Enterprise Linux 6"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Fix deferred", "package_name": "avahi", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Fix deferred", "package_name": "avahi", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Fix deferred", "package_name": "avahi", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/a:redhat:openshift:4", "fix_state": "Fix deferred", "package_name": "rhcos", "product_name": "Red Hat OpenShift Container Platform 4"}], "public_date": "2026-01-24T01:25:02Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-24401\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-24401\nhttps://github.com/avahi/avahi/commit/78eab31128479f06e30beb8c1cbf99dd921e2524\nhttps://github.com/avahi/avahi/issues/501\nhttps://github.com/avahi/avahi/security/advisories/GHSA-h4vp-5m8j-f6w3"], "statement": "This MODERATE impact flaw in Avahi's `avahi-daemon` can lead to a denial of service. An attacker on the local network could send a specially crafted, unsolicited mDNS response containing a recursive CNAME record, causing unbounded recursion and a crash. This affects systems where Avahi's record browsers explicitly use multicast, such as those utilizing `nss-mdns`.", "threat_severity": "Moderate"}

{"created": "2026-01-26T11:48:57.932689+00:00", "updated": "2026-10-23T19:30:18.252988+00:00", "vendors": ["avahi", "avahi$PRODUCT$avahi"]}