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

What is CVE-2026-18727?

CVE-2026-18727 is a medium-severity vulnerability in Redhat Enterprise Linux, published on 12 Aug 2026. It can only be exploited from the same machine or local network, with no action from the victim.

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.

Weakness: CWE-191

Which versions are affected by CVE-2026-18727?

It affects 1 product.

Products include Redhat Enterprise Linux.

How do I fix CVE-2026-18727?

Apply the vendor's patch.

Is CVE-2026-18727 being exploited?

There is no known exploitation of CVE-2026-18727 in the wild and no public exploit code.

Other vulnerabilities in Redhat Enterprise Linux

• CVE-2018-14667 Red Hat JBoss RichFaces Framework Expression Language Injection Exploited Critical 9.8
• CVE-2021-20325 Missing fixes for CVE-2021-40438 and CVE-2021-26691 in the versions of httpd, as shipped in Red Hat Enterprise Linux 8.5.0, causes a securit Critical 9.8
• CVE-2018-25011 Memory corruption in libwebp Critical 9.8
• CVE-2018-25014 Other in libwebp Critical 9.8
• CVE-2014-3585 Supply chain in redhat-upgrade-tool Critical 9.8

All Redhat Enterprise Linux vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as AZL-95922, DEBIAN-CVE-2026-18727, GHSA-g663-r6hr-qmc2, UBUNTU-CVE-2026-18727.