Instructlab: instructlab: arbitrary code execution due to hardcoded `trust_remote_code=true`

published 2026-04-22 6 mo ago modified 2026-10-26 13 d ago also GHSA-rxpq-xgqx-fr7p , PYSEC-2026-2522 , EUVD-2026-24752

cvss: 8.8; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.4%; EPSS 0.4% chance of exploitation in 30 days, percentile 38%
public exploits: 0; none known

A flaw was found in InstructLab. The `linux_train.py` script hardcodes `trust_remote_code=True` when loading models from HuggingFace. This allows a remote attacker to achieve arbitrary Python code execution by convincing a user to run `ilab train/download/generate` with a specially crafted malicious model from the HuggingFace Hub. This vulnerability can lead to complete system compromise.

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-6859 updated 2026-06-30 cvss 8.8

instructlab: InstructLab: Arbitrary code execution due to hardcoded `trust_remote_code=True`

Red Hat Enterprise Linux AI (RHEL AI) 3 rhelai3/bootc-cuda-rhel9, rhelai3/bootc-aws-cuda-rhel9, rhelai3/bootc-gcp-cuda-rhel9, rhelai3/bootc-azure-cuda-rhel9
affected: workaround, no fix available
Red Hat Enterprise Linux AI (RHEL AI) 3 rhelai3/bootc-rocm-rhel9, rhelai3/bootc-azure-rocm-rhel9
not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation: none
Automatable: no
Technical impact: total
Assessed: 6 mo ago (2026-04-23)

Exploit prediction

0.44% chance of exploitation in the next 30 days, higher than 38% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CNA	3.1	8.8	CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
CISA ADP	3.1	8.8	CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
NVD	3.1	8.8	CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
OSV	3.1	8.8	CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
GitHub	3.1	8.8	CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Affected packages

ecosystem	package	affected	fixed in
pypi	instructlab	<=0.26.1	no fix listed

Affected products

Red Hat Red Hat Enterprise Linux AI (RHEL AI) 3

Classification

Weakness

CWE-829 Inclusion of Functionality from Untrusted Control Sphere

References

access.redhat.com /security/cve/CVE-2026-6859
vdb-entry, web, vendor-advisory
bugzilla.redhat.com /show_bug.cgi?id=2459998
issue-tracking, web, vendor-advisory
security.access.redhat.com /data/csaf/v2/vex/2026/cve-2026-6859.json
nvd.nist.gov /vuln/detail/CVE-2026-6859
advisory
github.com /instructlab/instructlab
package
pypi.org /project/instructlab
package
github.com /advisories/GHSA-rxpq-xgqx-fr7p
advisory

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary