HashiCorp Nomad EUVD-2026-42349

Exploitation requires: (1) the Nomad client running on Linux with the Docker task driver enabled; (2) an operator having set allow_privileged to false expecting it to block privileged/host features (on the assumption this control is enforced); (3) the attacker holding valid Nomad ACL credentials with the submit-job capability; and (4) the attacker crafting a Docker task that specifies host namespace mode options (host network/PID/IPC). The limiting factors are that the attacker must already be an authenticated job submitter (PR:L), so this is not exploitable by fully unauthenticated outsiders, and impact is scoped to information disclosure from the host and workloads sharing that same client node rather than cross-cluster access.

The supplied CVSS 3.1 vector (AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N, score 7.7) indicates a network-reachable, low-complexity attack by an already-authenticated low-privilege principal (a valid job submitter), with a scope change reflecting that the container breaks out of its intended isolation to affect the host and neighboring workloads. Impact is confidentiality-only (C:H); the description explicitly limits the outcome to accessing information belonging to the host or other workloads, with no stated integrity or availability impact. There is no EPSS score, no POC, and no KEV listing in the provided data, so real-world exploitation pressure appears low and would be opportunistic rather than mass-scanned. The key limiting factor is that the attacker must already possess job-submission privileges on the cluster, which makes this primarily a multi-tenant/insider or compromised-credential concern rather than an unauthenticated internet-facing risk. This is a legitimate priority for shared multi-tenant Nomad clusters but a lower priority for single-tenant deployments where all job submitters are already trusted.

An attacker who holds valid Nomad job-submission credentials (for example, a low-trust tenant in a shared cluster or someone with stolen ACL tokens) submits a Docker task that requests host namespace mode despite allow_privileged being set to false. Because the restriction is not enforced, Nomad schedules the container in the host's namespaces, letting the attacker inspect host processes, network traffic, or data from other workloads running on the same client node. No public exploit code is identified at time of analysis, but the low attack complexity means a crafted job specification is sufficient.