Is CVE-2026-6859 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-6859 being exploited in the wild.

How severe is CVE-2026-6859?

High severity, with a CVSS score of 8.8, published 22 April 2026.

Which products and versions are affected?

instructlab (PyPI) ECOSYSTEM:introduced=0,last_affected=0.26.1.

Is there a fix for CVE-2026-6859?

No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

How is CVE-2026-6859 attacked?

It is attacked over the network, in a software library.

Am I affected by CVE-2026-6859?

Check whether you run instructlab (PyPI), Redhat Enterprise Linux Ai or Redhat Instructlab at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-6859: InstructLab arbitrary code execution via hardcoded trust_remote_code

CVE-2026-6859 · Severity: high · CVSS 8.8 · Published 2026-04-22

InstructLab, a tool used for training and interacting with large language models, contains a security flaw that could allow an attacker to take over a user's system. By tricking a user into downloading or training a malicious model from the HuggingFace Hub, an attacker can execute unauthorized commands on the victim's computer. This could lead to the theft of sensitive data or a complete compromise of the affected machine.

Vendors: PyPI, Redhat.

Quick answers

Is CVE-2026-6859 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-6859 being exploited in the wild.
How severe is CVE-2026-6859?: High severity, with a CVSS score of 8.8, published 22 April 2026.
Which products and versions are affected?: instructlab (PyPI) ECOSYSTEM:introduced=0,last_affected=0.26.1.
Is there a fix for CVE-2026-6859?: No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
How is CVE-2026-6859 attacked?: It is attacked over the network, in a software library.
Am I affected by CVE-2026-6859?: Check whether you run instructlab (PyPI), Redhat Enterprise Linux Ai or Redhat Instructlab at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

Technical details

A vulnerability exists in InstructLab's `linux_train.py` script where the `trust_remote_code=True` parameter is hardcoded during HuggingFace `from_pretrained()` calls. This bypasses security protections that normally prevent the execution of arbitrary code embedded within model files. A remote attacker can exploit this by hosting a malicious model on the HuggingFace Hub and convincing a user to interact with it using `ilab` commands (train, download, or generate). Successful exploitation results in arbitrary Python code execution with the privileges of the user running the script, potentially leading to full system compromise.

Affected products

Red Hat InstructLab -
Red Hat Red Hat Enterprise Linux AI (RHEL AI) 3 3.0

Identifiers

CVE-2026-6859
GHSA-rxpq-xgqx-fr7p
PYSEC-2026-2522

Timeline

2026-04-15: advisory: Initial release date of the VEX document
2026-04-22: disclosed: NVD publication date

References

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