Medium severity · published Sep 18, 2026
CVE-2026-85272
Open edX Platform: Path traversal via prefix-bypass in safe_extractall Path Validation
4.3
CVSS
0.5%
EPSS
No
On KEV
Description
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Confidentiality
None
Integrity
Low
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.5% · higher than 41% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
OP
openedx-platform · openedx
>= release/aspen.1, < release/ulmo.4; >= release/aspen.1, < release/verawood.1 · source: vendor
Affected product
OP
openedx-platform
openedx
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