CVE-2026-29179 — system
LOWCVE-2026-29179 is a low-severity (CVSS 3.3) CWE-863 vulnerability in october/system. A fix is available for october/system — see the affected versions and patch details below.
October CMS: Editor Sub-Permission Bypass for Asset and Blueprint File Operations
Exploitation Status
No confirmed exploitation observed yet
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-29179.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
Real-World Exposure
october/system🐘october/systemReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Packagist packages — download data is not available via public APIs for these ecosystems.
Description
Fine-grained sub-permission checks for asset and blueprint file operations were not enforced in the CMS and Tailor editor extensions. This only affects backend users who were explicitly granted editor access but had editor.cms_assets or editor.tailor_blueprints specifically withheld, an uncommon permission configuration. In this edge case, such users could perform file operations (create, delete, rename, move, upload) on theme assets or blueprint files despite lacking the required sub-permission. A related operator precedence error in the Tailor navigation also disclosed the theme blueprint directory tree under the same conditions.
Impact
- Only exploitable by authenticated backend users with
editoraccess who have been specifically denied theeditor.cms_assetsoreditor.tailor_blueprintssub-permissions - Does not affect default permission configurations where editor users typically have all sub-permissions granted
- Users without
editor.cms_assetscould manipulate theme asset files (delete, rename, move, upload, create directories) - Users without
editor.tailor_blueprintscould manipulate blueprint files (delete, rename, move, upload, create directories) - Users without
editor.tailor_blueprintscould view the theme blueprint navigation tree, disclosing file paths and directory structure
Patches
The vulnerability has been patched in v3.7.16 and v4.1.16. Fine-grained document type permission checks are now enforced on all asset and blueprint file operation commands, and the navigation node condition logic has been corrected. All users are encouraged to upgrade to the latest patched version.
Workarounds
- Restrict the
editorpermission to fully trusted administrators only - Remove the
editorpermission from any user who should not have asset or blueprint management access
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | october/system | ≥ 4.0.0&&< 4.1.16 | 4.1.16composer require october/system:^4.1.16 |
| 🐘Packagist | october/system | all versions | 3.7.16composer require october/system:^3.7.16 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for october/system, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update october/system to 4.1.16 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-29179 is resolved across your whole dependency graph.
Workarounds
Put an independent control in front of the weakness: restrict the affected endpoint or interface to trusted networks, require an additional authentication factor or proxy-level check, and invalidate existing sessions and credentials in case the flaw has already been used.
Frequently Asked Questions
Is CVE-2026-29179 in your dependencies?
Find it across Packagist, including transitive dependencies.