CVE-2026-113658: ApostropheCMS: Unauthenticated CSV import requests leave rejected uploads in the system temporary directory

Vulnerability summary

CVE-2026-113658 is a high (CVSS 7.5) Uncontrolled Resource Consumption vulnerability in apostrophecms apostrophe. EPSS estimates a 0.54% chance of exploitation in the next 30 days, higher than 44.5% of scored vulnerabilities.

Timeline

1. 20-10-2026
   PublishedVulnerability first disclosed.
2. 20-10-2026
   Last modifiedVulnerability information updated.

Description

ApostropheCMS is an open-source Node.js content management system. Prior to 4.33.0, the unauthenticated Rich Text CSV conversion route writes a multipart upload to the system temporary directory before checking its extension and does not remove the staged file when that validation rejects it. Repeated large rejected uploads, using the normal public CSRF cookie, can persistently consume temporary-disk capacity and may disrupt ApostropheCMS and other services that depend on the same partition. This issue is fixed in version 4.33.0.

• CWE-400Uncontrolled Resource ConsumptionThe product does not properly control the allocation and maintenance of a limited resource.
• CWE-459Incomplete CleanupThe product does not properly "clean up" and remove temporary or supporting resources after they have been used.
• CWE-770Allocation of Resources Without Limits or ThrottlingThe product allocates a reusable resource or group of resources on behalf of an actor without imposing any intended restrictions on the size or number of resources that can be allocated.