CVE-2026-18728: redhat enterprise_linux Integer Underflow (Wrap or Wraparound)

Vulnerability summary

CVE-2026-18728 is a medium (CVSS 6.5) Integer Underflow (Wrap or Wraparound) vulnerability in redhat enterprise_linux. EPSS estimates a 0.19% chance of exploitation in the next 30 days, higher than 8.2% of scored vulnerabilities.

Timeline

1. 13-08-2026
   PublishedVulnerability first disclosed.
2. 18-08-2026
   Last modifiedVulnerability information updated.

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.

• CWE-191Integer Underflow (Wrap or Wraparound)The product subtracts one value from another, such that the result is less than the minimum allowable integer value, which produces a value that is not equal to the correct result.