CVE-2026-74713

A flaw was found in the Linux kernel's vhost_iotlb module. Non-retiring tables within this module can continue to allocate entries even after reaching their configured limits. This allows a local attacker or a malicious guest operating system to trigger a continuous stream of IOTLB updates, leading to unbounded memory allocation. The primary consequence is a Denial of Service (DoS) due to resource exhaustion, potentially causing system instability or crashes.

This vulnerability is rated as Moderate impact for Red Hat Enterprise Linux because exploitation is restricted to denial of service, requiring local privileges or control over a guest virtual machine interacting with vhost/vDPA subsystems rather than allowing privilege escalation or remote code execution. In typical enterprise deployments, virtualization hosts running KVM or container environments with vDPA hardware acceleration expose these interfaces to guest workloads, where unconstrained mapping requests can deplete kernel memory. Systems that do not host virtual machines or do not utilize vhost-accelerated devices are unaffected by this condition during routine operations.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

Mitigation for this issue is either not available or the currently available options don't meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.