{"id":"CVE-2026-18728","title":"Open-iscsi: open-iscsi: integer underflow in iscsiuio ipv4 dhcp parsing","summary":"A flaw was found in open-iscsi. An integer underflow vulnerability in the `iscsiuio` component, specifically during IPv4 Dynamic Host Configuration Protocol (DHCP) parsing, allows a remote attacker on the same local network segment to ca…","severity":"medium","cvss":6.5,"cvssVector":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","cvssSource":"cna","cwe":["CWE-191"],"vendor":"Red Hat","product":"iscsi-initiator-utils","affected":["iscsi-initiator-utils (all versions)","iscsi-initiator-utils (all versions)"],"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"partial","timestamp":"2026-08-14T22:24:09.250067Z"},"published":"2026-08-13","updated":"2026-11-05","sourceUpdated":"2026-11-05T19:25:54.281Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-18728","references":[{"url":"https://access.redhat.com/security/cve/CVE-2026-18728"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2463029","label":"RHBZ#2463029"}],"tags":["cve.org"],"epss":0.00312,"epssPercentile":0.24276,"ingestedAt":"2026-11-05T22:38:31.542Z","slug":"CVE-2026-18728","body":"## Overview\n\nA flaw was found in open-iscsi. An integer underflow vulnerability in the `iscsiuio` component, specifically during IPv4 Dynamic Host Configuration Protocol (DHCP) parsing, allows a remote attacker on the same local network segment to cause a denial of service. By sending a specially crafted IPv4/UDP DHCP reply, the attacker can trigger an out-of-bounds read, leading to the `iscsiuio` process crashing. This issue affects systems where `iscsiuio` is actively handling IPv4 DHCP traffic.\n\n## Affected\n\n- `iscsi-initiator-utils (all versions)`\n- `iscsi-initiator-utils (all versions)`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.\n\n### Workarounds\n\nTo mitigate this issue, restrict network access to `iscsiuio`-managed interfaces. Configure firewall rules to limit DHCP/BOOTP traffic to only trusted infrastructure within the local broadcast domain. This reduces the exposure to untrusted systems that could send crafted IPv4 DHCP packets. If `iscsiuio` is actively using IPv4 DHCP, consider reconfiguring it to use static IP addresses or a different network configuration if feasible. Changes to network configuration may require a service restart.","depth":"sunlit","depthScore":36,"depthScoreParts":{"impact":35.8,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}