CVE-2026-32731 ApostropheCMS has Arbitrary File Write (Zip Slip / Path Traversal) in Import-Export Gzip Extraction
Attackers with content modify permissions can upload malicious archives to write arbitrary files outside the intended directory, potentially executing code.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-32731?
CVE-2026-32731 is a critical path traversal vulnerability in apostrophecms import-export, published on 18 Mar 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
ApostropheCMS is an open-source content management framework. Prior to version 3.5.3 of `@apostrophecms/import-export`, The `extract()` function in `gzip.js` constructs file-write paths using `fs.createWriteStream(path.join(exportPath, header.name))`. `path.join()` does not resolve or sanitise traversal segments such as `../`. It concatenates them as-is, meaning a tar entry named `../../evil.js` resolves to a path outside the intended extraction directory. No canonical-path check is performed before the write stream is opened. This is a textbook Zip Slip vulnerability. Any user who has been granted the Global Content Modify permission — a role routinely assigned to content editors and site managers — can upload a crafted `.tar.gz` file through the standard CMS import UI and write attacker-controlled content to any path the Node.js process can reach on the host filesystem. Version 3.5.3 of `@apostrophecms/import-export` fixes the issue.
Weakness: CWE-22
Which versions are affected by CVE-2026-32731?
2 open source packages ship an affected version, including @apostrophecms/import-export. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
@apostrophecms/import-export npm | All versions | 3.5.3 |
@apostrophecms/import-export npm | All versions | 3.5.3 |
Products include Apostrophecms Import-Export.
How do I fix CVE-2026-32731?
Upgrade @apostrophecms/import-export to 3.5.3 or later.
Upgrade, and resolve every user-supplied path against an allowed base folder before opening it. More about Path traversal.
Is CVE-2026-32731 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-32731 exists.
Public exploit code: 1 proofs of concept on GitHub.
Sources
Also known as GHSA-mwxc-m426-3f78.