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Vulnerability · Published Aug 12, 2026 · Assigned by redhat

CVE-2026-18727Open-iscsi: open-iscsi: integer underflow in iscsiuio dhcpv6 parsing

Medium 6.5

In plain English

A medium-severity security flaw in Red Hat Enterprise Linux 10 from Red Hat. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 21% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)6.5Medium
Exploit odds (30 days)0.3%top 78.9% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known

Official description

A flaw was found in open-iscsi's iscsiuio component. This vulnerability involves an integer underflow and out-of-bounds read during Dynamic Host Configuration Protocol for IPv6 (DHCPv6) packet parsing. Specifically, crafted DHCPv6 Advertise traffic with a short User Datagram Protocol (UDP) length can cause the DHCPv6 payload length to underflow. An unauthenticated attacker on an adjacent network segment can exploit this by sending specially crafted IPv6 UDP traffic while the client is in an active DHCPv6 exchange, leading to a denial of service due to a process crash or service disruption.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Debian:12open-iscsi2.1.8-1+deb12u1DEBIAN-CVE-2026-18727
Debian:13open-iscsino fix listedDEBIAN-CVE-2026-18727
Debian:14open-iscsi2.1.13-1DEBIAN-CVE-2026-18727
Ubuntu:22.04:LTSopen-iscsino fix listedUBUNTU-CVE-2026-18727
Ubuntu:24.04:LTSopen-iscsino fix listedUBUNTU-CVE-2026-18727
Ubuntu:26.04:LTSopen-iscsino fix listedUBUNTU-CVE-2026-18727
Ubuntu:26.10open-iscsino fix listedUBUNTU-CVE-2026-18727

Affected products (as reported)

VendorProductVersions
Red Hat Red Hat Enterprise Linux 10 see references
Red Hat Red Hat Enterprise Linux 9 see references

Weakness: CWE-191 · Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

References