CVE-2026-32731: ApostropheCMS is an open-source content management framework. Prior to version 3.5.3 of `@apostrophecms/import-export`, The `extract()` function in `g...

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.

Metrics

CVSS 3.1

9.9/10

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

EPSS Probability

0.43%

34.5th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-22

Affected Software

Vendor	Product	Versions
Apostrophecms	Import-Export	< 3.5.3

References

https://github.com/apostrophecms/apostrophe/security/advisories/GHSA-mwxc-m426-3f78Exploit, Vendor Advisory

Timeline

Published: Mar 18, 2026
Last Modified: Jun 17, 2026
Status: Analyzed

Frequently Asked Questions

What is CVE-2026-32731?

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.

How severe is CVE-2026-32731?

CVE-2026-32731 has a CVSS score of 9.9/10 (CRITICAL severity). The EPSS model estimates a 0.43% probability of exploitation in the next 30 days.

How do I fix CVE-2026-32731?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.