{"id":"CVE-2026-18728","state":"PUBLISHED","title":"Open-iscsi: open-iscsi: integer underflow in iscsiuio ipv4 dhcp parsing","description":"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 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.","publishedAt":"2026-08-13T03:13:55.805Z","updatedAt":"2026-08-18T14:37:36.014Z","severity":{"score":6.5,"label":"Medium","version":"3.1","vector":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","source":"redhat"},"assigner":"redhat","products":["Red Hat Red Hat Enterprise Linux 10","Red Hat Red Hat Enterprise Linux 9"],"affected":[{"vendor":"Red Hat","product":"Red Hat Enterprise Linux 10","packageName":"iscsi-initiator-utils","defaultStatus":"affected","collectionURL":"https://access.redhat.com/downloads/content/package-browser/","cpes":["cpe:/o:redhat:enterprise_linux:10"]},{"vendor":"Red Hat","product":"Red Hat Enterprise Linux 9","packageName":"iscsi-initiator-utils","defaultStatus":"affected","collectionURL":"https://access.redhat.com/downloads/content/package-browser/","cpes":["cpe:/o:redhat:enterprise_linux:9"]}],"references":["https://access.redhat.com/security/cve/CVE-2026-18728","https://bugzilla.redhat.com/show_bug.cgi?id=2463029"],"weaknesses":["CWE-191"],"ingestedAt":"2026-10-29T20:11:10.572Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/18xxx/CVE-2026-18728.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-18728","state":"PUBLISHED","datePublished":"2026-08-13T03:13:55.805Z","dateUpdated":"2026-08-18T14:37:36.014Z","assignerShortName":"redhat","assignerOrgId":"53f830b8-0a3f-465b-8143-3b8a9948e749","dateReserved":"2026-08-03T17:55:57.114Z"},"containers":{"cna":{"title":"Open-iscsi: open-iscsi: integer underflow in iscsiuio ipv4 dhcp parsing","descriptions":[{"lang":"en","value":"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 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."}],"affected":[{"vendor":"Red Hat","product":"Red Hat Enterprise Linux 10","packageName":"iscsi-initiator-utils","defaultStatus":"affected","collectionURL":"https://access.redhat.com/downloads/content/package-browser/","cpes":["cpe:/o:redhat:enterprise_linux:10"]},{"vendor":"Red Hat","product":"Red Hat Enterprise Linux 9","packageName":"iscsi-initiator-utils","defaultStatus":"affected","collectionURL":"https://access.redhat.com/downloads/content/package-browser/","cpes":["cpe:/o:redhat:enterprise_linux:9"]}],"references":[{"url":"https://access.redhat.com/security/cve/CVE-2026-18728","tags":["vdb-entry","x_refsource_REDHAT"]},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2463029","name":"RHBZ#2463029","tags":["issue-tracking","x_refsource_REDHAT"]}],"metrics":[{"other":{"content":{"value":"Moderate","namespace":"https://access.redhat.com/security/updates/classification/"},"type":"Red Hat severity rating"}},{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"ADJACENT_NETWORK","availabilityImpact":"HIGH","baseScore":6.5,"baseSeverity":"MEDIUM","confidentialityImpact":"NONE","integrityImpact":"NONE","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","version":"3.1"},"format":"CVSS"}],"problemTypes":[{"descriptions":[{"cweId":"CWE-191","description":"Integer Underflow (Wrap or Wraparound)","lang":"en","type":"CWE"}]}],"providerMetadata":{"shortName":"redhat","orgId":"53f830b8-0a3f-465b-8143-3b8a9948e749","dateUpdated":"2026-08-18T14:37:36.014Z"},"datePublic":"2026-08-12T18:05:24.879Z","x_redhatCweChain":"CWE-191: Integer Underflow (Wrap or Wraparound)","workarounds":[{"lang":"en","value":"To 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."}],"timeline":[{"lang":"en","time":"2026-04-26T20:41:55.000Z","value":"Reported to Red Hat."},{"lang":"en","time":"2026-08-12T18:05:24.879Z","value":"Made public."}],"credits":[{"lang":"en","value":"This issue was discovered by In partnership with Red Hat (Aisle.com) and Keith Linneman (Linneman Labs)."}],"x_generator":{"engine":"cvelib 1.8.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-08-14T22:24:09.250067Z","id":"CVE-2026-18728","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-08-14T22:24:20.561Z"}}]}}}