Instructlab: instructlab: path traversal allows arbitrary directory creation and file write

published 2026-04-22 6 mo ago modified 2026-10-26 13 d ago also GHSA-pqmg-c2j8-fq92 , PYSEC-2026-2521 , EUVD-2026-24736

cvss: 7.1; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.2%; EPSS 0.2% chance of exploitation in 30 days, percentile 5%
public exploits: 0; none known

A flaw was found in InstructLab. A local attacker could exploit a path traversal vulnerability in the chat session handler by manipulating the `logs_dir` parameter. This allows the attacker to create new directories and write files to arbitrary locations on the system, potentially leading to unauthorized data modification or disclosure.

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-2026-6855 updated 2026-09-23 cvss 7.1

instructlab: InstructLab: Path traversal allows arbitrary directory creation and file write

Red Hat Enterprise Linux AI (RHEL AI) 3 rhelai3/bootc-cuda-rhel9, rhelai3/bootc-rocm-rhel9, rhelai3/bootc-aws-cuda-rhel9, rhelai3/bootc-gcp-cuda-rhel9, rhelai3/bootc-azure-cuda-rhel9, rhelai3/bootc-azure-rocm-rhel9
affected: workaround, no fix available

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

0.16% chance of exploitation in the next 30 days, higher than 5% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CNA	3.1	7.1	CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
GitHub	3.1	7.1	CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
OSV	3.1	7.1	CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N

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-22 Improper Limitation of a Pathname to a Restricted Directory

References

access.redhat.com /security/cve/CVE-2026-6855
vdb-entry, web, vendor-advisory
bugzilla.redhat.com /show_bug.cgi?id=2460013
issue-tracking, web, vendor-advisory
nvd.nist.gov /vuln/detail/CVE-2026-6855
advisory
github.com /instructlab/instructlab
package
pypi.org /project/instructlab
package
github.com /advisories/GHSA-pqmg-c2j8-fq92
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