CVE-2026-86846: Out-of-bounds Write in Red Hat Fast Datapath for RHEL 10

This vulnerability in the Data Plane Development Kit (DPDK) lib/vhost vhost-crypto component allows a guest to supply an avail-ring descriptor index that is not properly bounds-checked. This results in an out-of-bounds write in the host vhost-crypto backend. The issue can cause a denial of service due to memory corruption. The CVSS 3.1 base score is 6.5, reflecting a locally exploitable flaw requiring low privileges and no user interaction, with a scope change and impact on availability only. The vendor advisory URL is provided but does not include explicit patch or remediation details in the input data.

The vulnerability can lead to an out-of-bounds write in the host environment, potentially causing a denial of service (availability impact). There is no confidentiality or integrity impact reported. Exploitation requires local access with low privileges and no user interaction. No known exploits in the wild have been reported.

Patch status is not yet confirmed — check the Red Hat advisory at https://access.redhat.com/security/cve/CVE-2026-86846 for current remediation guidance. Until an official fix is confirmed, limit exposure by restricting guest access and monitoring for unusual host behavior related to vhost-crypto operations.