# CVE-2026-86018: Part-DB attachment file size bypass in server-side downloads

Source: https://junglewise.ai/threats/cve-2026-86018-part-db-is-an-open-source-inventory-management-system-for  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-23. Updated: 2026-10-23  
License: CC BY 4.0 with a link back

CVE-2026-86018 · Severity: info · Published 2026-10-23

Part-DB is an open source system for managing electronic component inventories. When server-side attachment downloads are enabled, authenticated users can bypass the configured maximum file size limit and download arbitrarily large files, potentially filling up the server's disk and causing service outages.

Technologies: [Part-DB](https://junglewise.ai/threats/technologies/part-db-part-db). Vendors: [Part-DB](https://junglewise.ai/threats/vendors/part-db).

## Quick answers

**Is CVE-2026-86018 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-86018 being exploited in the wild.

**How severe is CVE-2026-86018?** Informational severity, published 23 October 2026.

**Which products and versions are affected?** Part-DB prior to 2.13.2.

**Is there a fix for CVE-2026-86018?** Yes: fixed in 2.13.2. Until then: Disable server-side attachment downloads by setting ALLOW_ATTACHMENT_DOWNLOADS=0 until the system can be upgraded to version 2.13.2 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-86018 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-86018?** Check whether you run Part-DB at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- Fixed in 2.13.2

Disable server-side attachment downloads by setting ALLOW_ATTACHMENT_DOWNLOADS=0 until the system can be upgraded to version 2.13.2 or later.

## Technical details

Part-DB's downloadURL() method in AttachmentSubmitHandler.php streams remote files directly to disk without enforcing MAX_ATTACHMENT_FILE_SIZE limits, unlike normal file uploads which are validated. An authenticated user with attachment editing permissions can supply a malicious external URL pointing to a large file; Part-DB will download it without size checks, causing disk exhaustion. This requires server-side attachment downloads to be enabled (ALLOW_ATTACHMENT_DOWNLOADS=1).

## Affected products

- Part-DB Part-DB prior to 2.13.2

## Timeline

- 2026-07-19: disclosed
- 2026-07-16: patched: version 2.13.2 released

## References

- [https://github.com/Part-DB/Part-DB-server/releases/tag/v2.13.2](https://github.com/Part-DB/Part-DB-server/releases/tag/v2.13.2)
- [https://github.com/Part-DB/Part-DB-server/security/advisories/GHSA-2whx-2cx7-qvq6](https://github.com/Part-DB/Part-DB-server/security/advisories/GHSA-2whx-2cx7-qvq6)

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