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{"affected_release": [{"advisory": "RHSA-2026:43588", "cpe": "cpe:/a:redhat:hummingbird:1", "impact": "important", "package": "unbound-main-1.25.2-0.1.hum1", "product_name": "Red Hat Hardened Images", "release_date": "2026-07-22T00:00:00Z"}], "bugzilla": {"description": "unbound: Unbound: Denial of Service via improper validation of DNS-over-QUIC client length", "id": "2503060", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2503060"}, "csaw": false, "cvss3": {"cvss3_base_score": "7.5", "cvss3_scoring_vector": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "status": "verified"}, "cwe": "CWE-770", "details": ["A flaw was found in Unbound when DNS-over-QUIC (DoQ) is enabled. An attacker could exploit improper validation of client-provided data length, leading to excessive memory allocation. This can cause the system to exceed its configured memory limits for QUIC connections, resulting in a Denial of Service (DoS) for new DoQ clients."], "mitigation": {"lang": "en:us", "value": "To mitigate this issue, disable DNS-over-QUIC (DoQ) in the Unbound configuration if it is not a required service. This can typically be achieved by commenting out or removing DoQ-related configuration options in `unbound.conf`. For example, remove or comment out lines such as `do-quic: yes` or `quic-port: 853`.\nAfter modifying the configuration, restart the Unbound service for the changes to take effect:\n```bash\nsystemctl restart unbound\n```\nWarning: Restarting the Unbound service will temporarily interrupt DNS resolution."}, "name": "CVE-2026-32665", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Not affected", "package_name": "unbound", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:6", "fix_state": "Not affected", "package_name": "unbound", "product_name": "Red Hat Enterprise Linux 6"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "unbound", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Not affected", "package_name": "unbound", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Not affected", "package_name": "unbound", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/a:redhat:openshift:4", "fix_state": "Affected", "package_name": "rhcos", "product_name": "Red Hat OpenShift Container Platform 4"}], "public_date": "2026-07-22T00:00:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-32665\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-32665"], "statement": "This Important flaw in Unbound, when configured for DNS-over-QUIC (DoQ), can lead to a denial of service for new DoQ clients. An attacker can exploit improper validation of client-provided data length, causing excessive memory allocation and exceeding configured limits. This impacts the availability of the DNS resolver for DoQ connections.", "threat_severity": "Important"}

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