openedx Platform up to verawood.0.x Archive Extraction extract_archive.py _is_bad_path path traversal

Summaryinfo

A vulnerability categorized as problematic has been discovered in openedx Platform up to verawood.0.x. This vulnerability affects the function _is_bad_path of the file openedx/core/lib/extract_archive.py of the component Archive Extraction. Such manipulation leads to path traversal. This vulnerability is listed as CVE-2026-85272. The attack may be performed from remote. There is no available exploit. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability, which was classified as problematic, has been found in openedx Platform up to verawood.0.x. Affected by this issue is the function _is_bad_path of the file openedx/core/lib/extract_archive.py of the component Archive Extraction. The manipulation with an unknown input leads to a path traversal vulnerability. Using CWE to declare the problem leads to CWE-22. The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory. Impacted is confidentiality, integrity, and availability. CVE summarizes:

Open edX Platform enables the authoring and delivery of online learning at any scale. From Aspen.1 until Ulmo and Verawood.1, openedx/core/lib/extract_archive.py uses _is_bad_path to validate safe_extractall targets by comparing resolved path strings with startswith instead of comparing path components. A course author or staff user with course import permission can submit a crafted .tar.gz archive through the import_olx flow initiated by cms.djangoapps.contentstore.views.import_export.import_handler. An archive member can therefore escape into a sibling course staging directory whose name shares the attacker's base64 directory prefix, causing limited cross-tenant file corruption. Zip archives are not practically affected because ZipFile.extractall strips parent traversal segments, and the advisory does not establish arbitrary filesystem writes, file reads, or direct code execution. This issue is fixed in Ulmo and Verawood.1.

The advisory is shared for download at github.com. This vulnerability is handled as CVE-2026-85272 since 09/03/2026. The exploitation is known to be easy. The attack may be launched remotely. Additional levels of successful authentication are necessary for exploitation. There are known technical details, but no exploit is available. The MITRE ATT&CK project declares the attack technique as T1006.

Upgrading to version release, ulmo.4, release or verawood.1 eliminates this vulnerability.

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Productinfo

Vendor

• openedx

Name

• Platform

Version

• release
• ulmo.0
• ulmo.1
• ulmo.2
• ulmo.3
• verawood
• verawood.0

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CPE 2.2info

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