CVE-2026-24267

Executive Summary

CVE-2026-24267 is a deserialization-of-untrusted-data vulnerability (CWE-502) in the NVIDIA NeMo Speech "speech data explorer" component, where malicious data crafted by an attacker can result in remote code execution. Any deployment of NVIDIA NeMo Speech that loads or ingests externally supplied data through the speech data explorer is potentially affected, and a successful exploit can yield code execution, privilege escalation, information disclosure, and data tampering. The vulnerability is unpatched with no public PoC or exploit code, but the CVSS 3.1 base score of 7.8 (High) and the local/reduced-vector profile — with user interaction required and no privileges needed — indicate a realistic attack path via social engineering or supply-chain delivery of a poisoned data artifact.

Technical Analysis

The root cause class is CWE-502: Deserialization of Untrusted Data. In this pattern, an application accepts a serialized object stream (or equivalent structured artifact) from a source outside its trust boundary and reconstructs in-memory objects from it without adequate validation, allow-listing, or safe-parsing controls. When the deserialization mechanism supports arbitrary object construction — as is the case with Python's pickle, dill, joblib, or similar object-graph serializers commonly used in machine-learning and data-science toolchains — the attacker controls not just data but the types and behaviors instantiated during loading. Execution of attacker-supplied logic then occurs during, or as a side effect of, the deserialization step.

NVIDIA NeMo Speech is a toolkit for speech AI workflows, and the "speech data explorer" component is the surface where curated speech/audio datasets and their metadata are inspected and manipulated. The NVD description states explicitly that malicious data created by an attacker could cause remote code execution through this component. That framing implies the trust boundary is crossed when the explorer loads attacker-influenced data — a dataset manifest, serialized annotation file, archive, or similar artifact that the explorer parses to render or process speech data. Because the description does not name specific functions, file formats, or loader routines, the precise sink is not disclosed here; no function names, file paths, or parameters are asserted beyond what the NVD text provides.

Two properties of the CVSS vector sharpen the analysis. First, AV:L (Local) with UI:R (User Interaction Required) and PR:N (No Privileges Required) describes an attack in which the victim must be induced to open, load, or point the tool at the crafted data, but the attacker needs no account on the target and no prior foothold. This is the signature of a malicious-file or poisoned-artifact delivery model, not a remotely reachable network service exploit. Second, the subscore C:H/I:H/A:H — full impact to confidentiality, integrity, and availability — reflects the post-exploitation potential once code executes in the tool's context: reading sensitive model, audio, or credential data (information disclosure), modifying datasets or outputs (data tampering), and disrupting the pipeline (availability). The 7.8 base score is High severity, determined by the full impact triad offset by the local vector and required user interaction.

The attack surface is therefore any workflow in which a user of NeMo Speech ingests speech data or associated artifacts that originated from an untrusted party — downloaded public datasets, shared research corpora, third-party model or annotation packages, or internal transfers from lower-trust environments. No evidence of a public proof-of-concept, exploit code, or Nuclei template exists at this time, and the CVE is not listed in CISA KEV, so there is no confirmed in-the-wild exploitation. The risk is nonetheless material for organizations that treat external ML datasets as trusted input, because the weaponization primitive for CWE-502 is well understood and low-complexity once an attacker can influence the serialized content.

Exploitation Scenarios

Because no public PoC exists, the following chain is described at the vulnerability-class level, consistent with the NVD description; it does not assert specific function names, endpoints, or code constructs beyond what the advisory states.

1. Reconnaissance / target identification. The attacker identifies an organization or individual that uses NVIDIA NeMo Speech and the speech data explorer, typically research groups, ML engineering teams, and speech-AI product teams. Targets are often discoverable through published model/dataset artifacts, conference releases, internal dataset exchange, or exposed tooling. Shodan dorks such as http.title:"NeMo Speech" or http.html:"speech data explorer" may surface exposable instances where such tooling is published.

2. Weaponized data delivery. The attacker crafts a "malicious data" artifact — the exact format is not disclosed by the advisory, but by the CWE-502 class it is a serialized or structured object consumed by the explorer. The artifact is placed where the victim is likely to load it: a public dataset repository, an email or file-share attachment, a "model/annotation pack" offered for evaluation, or a compromised update to a shared corpus. This matches the PR:N / UI:R profile: no privileges are needed, but the victim must act.

3. Trigger of the flaw class. The victim opens or loads the crafted data in the speech data explorer. The component deserializes or parses the artifact without adequate controls, reconstructing attacker-controlled objects whose construction or methods execute during deserialization. Execution thus occurs in the context of the NeMo Speech process running on the victim's host.

4. Post-exploitation impact. With code execution achieved (C:H/I:H/A:H), the attacker can read sensitive files, environment variables, credentials, and proprietary speech data (information disclosure); alter datasets, annotations, or generated outputs (data tampering); and disrupt the pipeline (availability). If the process runs with elevated permissions, the described "escalation of privileges" applies. Persistence and lateral movement depend on host configuration and are not specified by the advisory.

No public exploit, PoC, or Nuclei template is available; this chain is inferred from the vulnerability class and CVSS vector.

Impact Assessment

Business impact centers on the integrity of the ML/speech data pipeline and the confidentiality of the host that runs NeMo Speech. CVSS 3.1 base score 7.8 (High) decomposes as AV:L, AC:L, PR:N, UI:R, S:U, C:H, I:H, A:H. The low attack complexity (AC:L) and no-privileges-required condition (PR:N) make this attractive where user interaction (UI:R) can be socially engineered. Full confidentiality and integrity impact means stolen datasets/credentials and silently corrupted training corpora — a serious concern for organizations whose downstream models and products depend on that data. Scope is Unchanged (S:U), so impact is confined to the vulnerable component's security authority, but that authority may include file-system access of the hosting process.

Blast radius is defined by how many users load external data into the explorer and by the privileges of the loading process. A workstation running the tool interactively limits blast radius to that host; a shared server or CI/ML pipeline that deserializes contributed datasets could spread impact across the data supply chain. No EPSS score has been published by FIRST.org, no CISA KEV listing exists, and no affected version list is available, so risk scoring must rely on the CVSS profile and asset exposure rather than observed exploitation.

Detection Guidance

Sigma Rule

title: Suspicious NeMo Speech Data Explorer Deserialization Attempt
id: 8f3a2c14-nemo-24267-4b1e-9c7d-2a1f6e0b9d42
status: experimental
description: Detects process execution patterns consistent with deserialization of untrusted data (CWE-502) by the NVIDIA NeMo Speech data explorer component (CVE-2026-24267).
references:
  - https://nvd.nist.gov/vuln/detail/CVE-2026-24267
author: valtersit.com
date: 2026/01/01
logsource:
  category: process_creation
  product: linux
detection:
  selection_parent:
    ParentImage|endswith:
      - '/python'
      - '/python3'
      - '/nemo_speech'
  selection_cmd:
    CommandLine|contains:
      - 'speech_data_explorer'
      - 'SpeechDataExplorer'
      - 'nemo.collections.asr'
  selection_child:
    Image|endswith:
      - '/sh'
      - '/bash'
      - '/curl'
      - '/wget'
      - '/nc'
      - '/python'
      - '/python3'
  condition: selection_parent and selection_cmd and selection_child
falsepositives:
  - Legitimate ML tooling that spawns helper interpreters
level: high

YARA Rule

rule CVE_2026_24267_Nemo_Speech_Deserialization
{
    meta:
        description = "Detects potential CWE-502 serialized payloads targeting NVIDIA NeMo Speech data explorer (CVE-2026-24267)"
        author = "valtersit.com"
        date = "2026-01-01"
        reference = "https://nvd.nist.gov/vuln/detail/CVE-2026-24267"
        severity = "high"

    strings:
        $py_pickle = { 80 04 95 }            // pickle protocol 4 frame opcode
        $py_pickle2 = { 80 05 95 }           // pickle protocol 5 frame opcode
        $reduce     = "cos\nsystem" nocase
        $reduce2    = "R\n" nocase
        $os_system  = "posix\nsystem" nocase
        $subprocess = "subprocess\nPopen" nocase
        $eval       = "builtins\neval" nocase
        $nemo       = "speech_data_explorer" nocase
        $nemo2      = "SpeechDataExplorer" nocase

    condition:
        (uint16(0) == 0x8b1f or uint32(0) == 0x04034b50 or uint8(0) == 0x80) and
        (any of ($py_pickle*) or any of ($reduce*) or $os_system or $subprocess or $eval) and
        any of ($nemo*)
}

Suricata IDS Rule

alert http any any -> any any (msg:"CVE-2026-24267 NVIDIA NeMo Speech Data Explorer untrusted deserialization artifact transfer"; flow:established,to_server; http.method; content:"POST"; http.uri; content:"upload"; nocase; file.data; content:"|80 04 95|"|"|80 05 95|"; fast_pattern; filestore; filestore:name,"nemo_payload"; classtype:attempted-user; reference:cve,2026-24267; reference:url,nvd.nist.gov/vuln/detail/CVE-2026-24267; sid:202624267; rev:1;)

Elastic Detection

process where event.type == "start" and
  process.parent.name in ("python", "python3") and
  process.parent.args : ("*speech_data_explorer*", "*SpeechDataExplorer*", "*nemo.collections.asr*") and
  process.name in ("sh", "bash", "curl", "wget", "nc", "python", "python3")

Splunk SPL Query

index=endpoint (source="XmlWinEventLog:Microsoft-Windows-Sysmon/Operational" OR sourcetype="linux:sysmon" OR sourcetype="auditd")
(EventCode=1 OR type=SYSCALL)
| search (CommandLine="*speech_data_explorer*" OR CommandLine="*SpeechDataExplorer*" OR CommandLine="*nemo.collections.asr*")
| eval risk="CVE-2026-24267 potential NeMo Speech deserialization RCE"
| table _time host user ParentImage ParentCommandLine Image CommandLine risk
| sort - _time

Wazuh OSSEC Rule

<group name="nemo_speech,cve_2026_24267,">
  <rule id="100267" level="12">
    <if_sid>5925</if_sid>
    <field name="audit.command">speech_data_explorer</field>
    <description>CVE-2026-24267: Possible untrusted deserialization in NVIDIA NeMo Speech data explorer - investigate immediately.</description>
    <mitre>
      <id>T1203</id>
    </mitre>
    <group>cve_2026_24267,</group>
  </rule>

  <rule id="100268" level="12">
    <if_sid>5925</if_sid>
    <field name="audit.parent_command">python</field>
    <field name="audit.command">/bin/sh|/bin/bash|curl|wget|nc</field>
    <description>CVE-2026-24267: Child shell/network process spawned under NeMo Speech data explorer - possible code execution.</description>
    <mitre>
      <id>T1059</id>
    </mitre>
    <group>cve_2026_24267,</group>
  </rule>
</group>

Mitigation & Patch Guidance

Patch confidence is 0/4 — UNPATCHED. No vendor fix, workaround, affected-version range, or patch reference is available from any tracked source. NVIDIA has not published remediation guidance in the data supplied.

1) Immediate mitigations.

• Treat all external speech datasets, annotation packs, manifests, and model artifacts as untrusted. Do not load data of unknown provenance into the speech data explorer.
• Isolate risk: run NeMo Speech in a container or VM with no access to production credentials, shared file systems, or sensitive datasets, and with the lowest practical privileges (addresses the "escalation of privileges" component).
• Require integrity verification (hashes/signatures) for any dataset entering the pipeline, and route contributed data through a review/sandbox step before it reaches the explorer.
• Monitor for unauthorized data ingestion and for the process-execution anomalies described in the Detection Guidance section.

2) Patch/upgrade steps.

• No patch is available. Monitor NVIDIA's official security bulletin and NVIDIA product security pages for CVE-2026-24267; apply the vendor fix as soon as it is released.
• Track NVD (https://nvd.nist.gov/vuln/detail/CVE-2026-24267) and NVIDIA's advisories for an affected-version list and fixed release.
• When a fix ships, inventory all NeMo Speech installations and upgrade promptly, prioritizing shared/pipeline hosts over single-user workstations.

3) Long-term hardening.

• Replace unsafe deserialization with safe formats (e.g., JSON, CSV) or a hardened serializer with strict allow-listing for any component that consumes external ML artifacts.
• Adopt a data-supply-chain policy: provenance tracking, signing, and vetting for every dataset and model that enters the environment.
• Apply least-privilege execution and network egress controls around ML tooling to contain post-exploitation impact (C:H/I:H/A:H).
• Maintain asset visibility for ML tooling and prioritize patching based on exposure and privilege of the hosting process.

References

• NVD — CVE-2026-24267: https://nvd.nist.gov/vuln/detail/CVE-2026-24267
• NVIDIA Product Security (monitor for CVE-2026-24267 advisory): https://www.nvidia.com/en-us/security/
• MITRE CWE-502 — Deserialization of Untrusted Data: https://cwe.mitre.org/data/definitions/502.html
• FIRST EPSS (no score yet published for this CVE): https://api.first.org/data/v1/epss?cve=CVE-2026-24267
• CISA Known Exploited Vulnerabilities catalog (CVE-2026-24267 not currently listed): https://www.cisa.gov/known-exploited-vulnerabilities-catalog

No threat actor campaigns or exploit-in-the-wild evidence are associated with CVE-2026-24267 at the time of writing; the CVE is not in CISA KEV, no public PoC or exploit code is available, and no EPSS score has been published.