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Fencer Intel
critical 10.0

CVE-2026-32731 json

ApostropheCMS has Arbitrary File Write (Zip Slip / Path Traversal) in Import-Export Gzip Extraction

published 7mo ago modified 4mo ago also GHSA-mwxc-m426-3f78 , EUVD-2026-12978

cvss
10.0
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.6%
EPSS 0.6% chance of exploitation in 30 days, percentile 46%
public exploits
0
none known

Summary

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.

Patch / fix

  • npm @apostrophecms/import-export 3.5.3
  • apostrophecms import-export 3.5.3

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CISA SSVC

Exploitation
Proof of concept is public
Automatable
no
Technical impact
total
Assessed
7mo ago

Exploit prediction

0.55% chance of exploitation in the next 30 days, higher than 46% of all scored CVEs (FIRST EPSS, 2026-11-09).

Exploits and checks

  • github.com https://github.com/apostrophecms/apostrophe/security/advisories/GHSA-mwxc-m426-3f78 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 10.0 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
GitHub 3.1 9.9 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

Affected packages

ecosystem package affected fixed in
npm @apostrophecms/import-export
<3.5.3
3.5.3

Affected products

  • apostrophecms import-export

Classification

Weakness
  • CWE-22 Improper Limitation of a Pathname to a Restricted Directory

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.