---
title: "CVE-2026-32731: ApostropheCMS has Arbitrary File Write (Zip Slip / Path Traversal) in Import-Export Gzip Extraction"
url: https://erroneo.us/security/cve/CVE-2026-32731/
description: "CVE-2026-32731 (@apostrophecms/import-export (npm)): ApostropheCMS is an open-source content management framework. Prior to version 3.5.3 of…"
type: vulnerability-record
section: "Security Digest"
date_published: 2026-03-18
date_modified: 2026-03-19
publisher: erroneo.us
author: erroneo.us Security Desk
cve: "CVE-2026-32731"
kev: false
cvss: 10
epss: 0.00615
license: All rights reserved. Quote with attribution and a link.
---

# CVE-2026-32731: ApostropheCMS has Arbitrary File Write (Zip Slip / Path Traversal) in Import-Export Gzip Extraction

**Signal:** Critical, preconditions apply. Severe if exploited, but exploitation needs conditions that may not apply to you. (Computed from CISA KEV, EPSS and CVSS; not an editorial verdict.)

## Should you act?

- Not in CISA KEV , but CISA’s SSVC assessment records a public proof-of-concept, so attack code exists.
- EPSS 0.6% , percentile 49: FIRST’s model estimates a 0.6% chance of exploitation activity in the next 30 days, higher than 49% of all scored CVEs (low). EPSS is a probability, not a verdict.
- Needs an account (low (any account)). Exposure depends on who can log in.
- Only applies if your dependency tree includes @apostrophecms/import-export (npm) <= 3.5.2, fixed in 3.5.3 . Check your lockfile, including transitive dependencies.

## What it is

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.

## Affected packages

- npm `@apostrophecms/import-export` <= 3.5.2 → fixed: 3.5.3

## Affected products (CVE record)

- apostrophecms import-export: < 3.5.3

## Severity

- GitHub_M CVSS 3.1: 10 `CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H`
- GitHub CVSS 3.1: 9.9 `CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H`

## Exploitation

- CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
- CISA SSVC assessment: exploitation poc , automatable no , technical impact total .
- FIRST EPSS (model of 2026-10-21): 0.61% probability of exploitation activity in the next 30 days; percentile 49.

## Sources

- [GitHub Advisory GHSA-mwxc-m426-3f78](https://github.com/advisories/GHSA-mwxc-m426-3f78)
- [CVE.org record CVE-2026-32731](https://www.cve.org/CVERecord?id=CVE-2026-32731)
- [NVD entry CVE-2026-32731](https://nvd.nist.gov/vuln/detail/CVE-2026-32731)
- [github.com](https://github.com/apostrophecms/apostrophe/security/advisories/GHSA-mwxc-m426-3f78)

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Source page: https://erroneo.us/security/cve/CVE-2026-32731/ · Security Digest: https://erroneo.us/security/ · More: https://erroneo.us/llms.txt