CVE-2026-65126

Executive Summary

CVE-2026-65126 is a vulnerability in the NVIDIA Infrastructure Controller for Linux in which an attacker can cause improper enforcement of a behavioral workflow. A successful exploit may result in data tampering, denial of service, and information disclosure. The CVSS 3.1 base score is 5.0 (Medium), reflecting a network-reachable flaw that requires high attack complexity and low privileges — meaning the attacker must already hold some level of access (e.g., a low-privileged account or session) but needs no user interaction and can trigger the issue remotely. Because the vulnerability is unpatched, affected deployments of the NVIDIA Infrastructure Controller for Linux should be treated as at-risk until NVIDIA publishes a fix.

Technical Analysis

The vulnerability is classified as CWE-841: "Improper Enforcement of Behavioral Workflow." This weakness class describes a scenario in which the product does not correctly enforce the sequence, state, or conditions of a multi-step workflow, allowing an actor to reach a state or perform an action that should have been prohibited. Unlike a memory-safety bug or an injection flaw, CWE-841 is a logic/state-machine weakness: the code path is reachable and the inputs may be well-formed, but the intended constraints on "what may happen next" are not applied.

What the public description supports (and nothing more):

• Product: NVIDIA Infrastructure Controller for Linux.
• Weakness: improper enforcement of a behavioral workflow (CWE-841).
• Outcome on successful exploit: data tampering, denial of service, and information disclosure.
• Access requirements per the CVSS vector: network vector (AV:N), high attack complexity (AC:H), low privileges required (PR:L), no user interaction (UI:N), scope unchanged (S:U). Confidentiality, integrity, and availability impacts are all Low (C:L/I:L/A:L).

The attack surface, therefore, is any network-reachable workflow or state-transition interface exposed by the Infrastructure Controller — for example, a multi-step provisioning, configuration, onboarding, or management operation whose steps are validated individually but not as an ordered, authenticated sequence. Because the flaw is in workflow enforcement rather than a specific parser, exploitation depends on reaching a valid intermediate state and then driving the controller into an unintended terminal state.

Important limitation on specificity: the NVD description and CNA title provided for this CVE contain no function names, class names, URL paths, API endpoints, parameter names, or file paths. No affected version range, no OSV package mapping, and no vendor advisory are available. Accordingly, this report intentionally does NOT name any internal component, endpoint, or parameter. Any such detail would be fabricated and is therefore omitted. The attack-chain discussion below stays at the vulnerability-class level.

CVSS subscores imply:

• AV:N — the vulnerable workflow interface is reachable over the network, so exploitation does not require local shell access.
• AC:H — the attacker must satisfy non-trivial preconditions: reaching the correct workflow state, timing or sequencing the requests, or otherwise meeting conditions that are not guaranteed on every attempt.
• PR:L — a low-privileged account or session is sufficient; no administrative credential is required.
• UI:N — the target does not need to click, confirm, or otherwise cooperate.
• Scope Unchanged — the flaw's effect stays within the security authority of the vulnerable component.
• C:L/I:L/A:L — all three impact categories are Low, consistent with tampering with a limited set of workflow-controlled values, partial service degradation, and limited information exposure rather than full system compromise.

Exploitation Scenarios

No public PoC, exploit code, or Nuclei template exists for CVE-2026-65126. The attack chain below is inferred strictly from the vulnerability class (CWE-841) and the CVSS/impact data; it does not describe specific functions, endpoints, or parameters, because none are given in the source data.

1. Reconnaissance / target identification An attacker identifies a reachable NVIDIA Infrastructure Controller for Linux instance on the network. This is a network-vector (AV:N) flaw, so the exposed management/workflow interface is the target. The attacker determines what authenticated access is available — the vector requires only low privileges (PR:L), so any low-privileged account, service credential, or session obtained through prior phishing, credential reuse, or another foothold is sufficient to begin probing.

2. Triggering the specific flaw class The attacker initiates the intended multi-step workflow and then violates its expected ordering or state preconditions. In a CWE-841 scenario, the controller fails to enforce that each step occurs in the correct sequence, that the actor is authorized for the workflow's terminal action (not just the initial one), or that a given transition is only reachable from a permissible prior state. Because the vector is AC:H, the attacker likely needs to satisfy specific, possibly unstable conditions — certain prior state, race/timing between steps, or a particular combination of parameters — rather than performing a single unauthenticated request. Successful triggering moves the controller into a state the workflow designer did not intend to allow.

3. Payload / execution method at the vulnerability-class level There is no buffer, query, or command payload in the classic sense. The "payload" is the crafted workflow invocation: an out-of-order step, a replayed step, a skipped step, or a transition attempted from an unintended state. The weakness is that the controller trusts the workflow's position rather than re-validating it, so the crafted invocation is accepted. No specific API path, method, or parameter can be named from the available data.

4. Post-exploitation impact On success, per the CNA description, the attacker can achieve:

• Data tampering (I:L) — modifying workflow-controlled data, configuration, or state that should have been protected from a low-privileged actor.
• Denial of service (A:L) — degrading or disrupting the workflow function or the controller's availability, at least partially.
• Information disclosure (C:L) — accessing information the attacker's privilege level should not permit, such as data surfaced by an improperly reachable workflow state. The Low ratings on all three impacts indicate limited, not total, loss of each property; scope remains unchanged, so the impact stays within the controller's own security boundary.

Impact Assessment

Business impact centers on the integrity and availability of the infrastructure management plane. NVIDIA Infrastructure Controller for Linux is used to manage and provision infrastructure; a workflow-enforcement flaw in that plane is attractive because success can let a low-privileged actor tamper with managed state rather than merely read it. The three-way impact (data tampering, denial of service, information disclosure), even at Low severity each, is operationally meaningful: tampering with workflow-controlled data can push incorrect configuration to downstream systems, while a DoS on the controller can remove management visibility and control at exactly the moment operators need it.

Affected systems: deployments of the NVIDIA Infrastructure Controller for Linux. No affected version range is available from any tracked source, so scope cannot be narrowed by version — every deployment should be assumed potentially affected pending NVIDIA guidance.

Blast radius is bounded by:

• PR:L — the attacker must already hold low privileges; this is not a pre-authentication flaw.
• AC:H — exploitation is conditional and not reliably automatable from the public data; mass exploitation is unlikely without a detailed PoC, which does not exist publicly.
• C:L/I:L/A:L and S:U — impacts are limited in magnitude and stay within the component's security authority. Mitigating the blast radius does NOT eliminate risk: an insider or a low-privileged foothold can still tamper with managed infrastructure state. The CVSS 3.1 base score is 5.0.

Detection Guidance

Because the flaw is a workflow/state-logic weakness (CWE-841), detection should focus on anomalous workflow sequences — out-of-order, replayed, skipped, or state-mismatched operations against the Infrastructure Controller — rather than on classic payload signatures. The rules below are written for that behavioral detection model. Field names and product identifiers are generic where the source data provides none; tune them to your actual telemetry before deployment.

Sigma Rule

title: NVIDIA Infrastructure Controller - Improper Workflow Enforcement (CVE-2026-65126)
id: 7c1f9a2e-3b64-4d51-9e08-cve202665126
status: experimental
description: Detects anomalous or out-of-order workflow operations against the NVIDIA Infrastructure Controller for Linux that may indicate attempted exploitation of CWE-841 improper behavioral workflow enforcement.
references:
  - https://nvd.nist.gov/vuln/detail/CVE-2026-65126
author: valtersit.com
date: 2026/01/01
logsource:
  product: nvidia
  service: infrastructure_controller
detection:
  selection_state_error:
    event.outcome: 'failure'
    message|contains:
      - 'workflow'
      - 'state'
      - 'transition'
      - 'sequence'
  selection_privilege_low:
    user.roles: 'low'
  condition: selection_state_error and selection_privilege_low
falsepositives:
  - Legitimate workflow retries after transient errors
  - Authorized bulk reconfiguration jobs
level: medium
tags:
  - attack.t1190
  - cve.2026.65126

YARA Rule

rule CVE_2026_65126_NVIDIA_Infrastructure_Controller_Workflow
{
    meta:
        description = "Heuristic detection for artifacts referencing the NVIDIA Infrastructure Controller for Linux workflow enforcement flaw (CVE-2026-65126)"
        author = "valtersit.com"
        date = "2026-01-01"
        reference = "https://nvd.nist.gov/vuln/detail/CVE-2026-65126"
        cve = "CVE-2026-65126"
        cwe = "CWE-841"

    strings:
        $prod1 = "Infrastructure Controller" ascii nocase
        $prod2 = "infrastructure-controller" ascii nocase
        $work1 = "workflow" ascii nocase
        $work2 = "state transition" ascii nocase
        $cve   = "CVE-2026-65126" ascii nocase

    condition:
        filesize < 5MB and
        (
            (any of ($prod*)) and
            (any of ($work*))
        )
        or $cve
}

Suricata IDS Rule

alert http any any -> any any (msg:"CVE-2026-65126 NVIDIA Infrastructure Controller Improper Workflow Enforcement Attempt"; flow:established,to_server; http.user_agent; content:"NVIDIA"; nocase; http.uri; content:"workflow"; nocase; threshold:type both, track by_src, count 20, seconds 60; classtype:attempted-admin; reference:cve,2026-65126; reference:url,nvd.nist.gov/vuln/detail/CVE-2026-65126; sid:900651260; rev:1;)

Elastic Detection

sequence by user.name, source.ip with maxspan=2m
  [any where event.category == "authentication" and event.outcome == "success" and user.roles == "low"]
  [any where event.category == "web" and event.action in ("workflow_step", "state_transition") and event.outcome == "failure"]
  [any where event.category == "web" and event.action in ("workflow_step", "state_transition") and event.outcome == "success"]

Splunk SPL Query

index=nvidia sourcetype=infrastructure_controller:*
| search (workflow OR "state transition" OR "sequence") (result=failure OR outcome=failure OR status=4*)
| stats count min(_time) as first_seen max(_time) as last_seen values(user) as users values(src_ip) as src_ips by user, src_ip, workflow_id
| where count > 10
| convert ctime(first_seen) ctime(last_seen)
| sort - count

Wazuh OSSEC Rule

<group name="nvidia,infrastructure_controller,cve-2026-65126,">
  <rule id="100651" level="10">
    <decoded_as>json</decoded_as>
    <field name="product">Infrastructure Controller</field>
    <match>workflow</match>
    <regex>failure|out of sequence|invalid state|transition</regex>
    <description>CVE-2026-65126: Possible NVIDIA Infrastructure Controller improper workflow enforcement attempt</description>
    <mitre>
      <id>T1190</id>
    </mitre>
  </rule>
</group>

Mitigation & Patch Guidance

Patch confidence: 0/4 (UNPATCHED — no patch evidence from any tracked source). No vendor fix, workaround, affected-version range, or advisory is currently tracked for CVE-2026-65126. There is no patch to reference and no confirmed affected-version boundary, so all mitigations below are compensating controls.

1. Immediate mitigations (interim, until a fix exists)

• Restrict network reachability of the NVIDIA Infrastructure Controller for Linux to trusted management networks only; the flaw is AV:N, so reducing exposure directly reduces attack surface. Place the controller behind a management VLAN, VPN, or jump host.
• Apply least privilege aggressively. Because exploitation requires only PR:L, audit and minimize the number of low-privileged accounts and service credentials that can initiate workflows on the controller. Remove or disable unused accounts.
• Enforce strong authentication (MFA) on the controller and rotate any credentials that could grant a low-privileged session.
• Monitor for anomalous workflow behavior (out-of-order, replayed, or skipped steps) using the detection rules in the previous section; treat repeated workflow state errors from a single low-privileged source as a potential exploitation attempt.
• Rate-limit and alert on high-frequency workflow/state-transition requests per source to make the AC:H exploitation conditions harder to satisfy at scale.

2. Patch/upgrade steps

• No patch is available; patch confidence is 0/4. Do NOT apply unofficial fixes or third-party binaries.
• Monitor NVIDIA's official security bulletin channel and the NVD entry for CVE-2026-65126 at https://nvd.nist.gov/vuln/detail/CVE-2026-65126 for the first authoritative advisory and affected-version list.
• When NVIDIA publishes a fixed version: identify affected instances, back up controller configuration, stage the update in a non-production environment, validate workflow correctness, then roll out to production. Because no affected-version range is documented, assume all instances are affected until NVIDIA states otherwise.

3. Long-term hardening

• Adopt a formal change-control and patch-management process for infrastructure-management components, tracked against vendor advisories and CVE feeds.
• Segment and zero-trust the management plane so a compromise of a low-privileged user does not translate into control-plane tampering.
• Require re-authorization for each step of privileged workflows (defense-in-depth against CWE-841 class flaws) wherever the product allows it via external policy, and log every state transition for forensic review.
• Continuously monitor EPSS and CISA KEV for this CVE; EPSS is currently unassigned and it is not in KEV, so no exploit-in-the-wild evidence exists at this time. Re-assess if either changes.

References

• NVD — CVE-2026-65126: https://nvd.nist.gov/vuln/detail/CVE-2026-65126
• MITRE CWE-841 — Improper Enforcement of Behavioral Workflow: https://cwe.mitre.org/data/definitions/841.html
• MITRE ATT&CK T1190 — Exploit Public-Facing Application: https://attack.mitre.org/techniques/T1190/
• NVIDIA Product Security Incident Response Team (PSIRT) advisories (vendor advisory channel; no advisory for this CVE is currently published): https://www.nvidia.com/en-us/security/
• CISA Known Exploited Vulnerabilities Catalog (CVE-2026-65126 is NOT listed as of this report): https://www.cisa.gov/known-exploited-vulnerabilities-catalog

Threat actor / exploit-in-the-wild status: No public PoC, no exploit code, no Nuclei template, and no CISA KEV listing exist for CVE-2026-65126. There is no evidence of active exploitation or named threat-actor campaigns. EPSS has not yet been scored by FIRST.org. Detection and mitigation guidance above is based on the vulnerability class and CVSS profile, not on observed exploitation.