# CVE-2026-53724: Parse Server stored XSS via trailing dot filename bypass

Source: https://junglewise.ai/threats/cve-2026-53724-parse-server-stored-xss-via-trailing-dot-filename-bypass  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-06-12. Updated: 2026-06-19  
License: CC BY 4.0 with a link back

CVE-2026-53724 · Severity: medium · CVSS 4 · Published 2026-06-12

Parse Server, an open-source backend framework, contains a vulnerability in how it handles file uploads. An attacker can bypass security restrictions to upload malicious files (like SVG images containing scripts) by adding a dot to the end of a filename. If a user opens one of these files, the attacker could execute malicious code in the user's browser, potentially leading to unauthorized actions or data theft.

Technologies: [parse-server (npm)](https://junglewise.ai/threats/technologies/parse-server). Vendors: [npm](https://junglewise.ai/threats/vendors/npm).

## Quick answers

**Is CVE-2026-53724 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-53724 being exploited in the wild.

**How severe is CVE-2026-53724?** Medium severity, with a CVSS score of 4, published 12 June 2026.

**Which products and versions are affected?** parse-server (npm) SEMVER:introduced=9.0.0,fixed=9.9.1-alpha.4.

**Is there a fix for CVE-2026-53724?** Yes. parse-server (npm): upgrade to 9.9.1-alpha.4 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-53724 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-53724?** Check whether you run parse-server (npm) 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

- parse-server (npm): upgrade to 9.9.1-alpha.4 or later

  ```sh
  npm install parse-server@9.9.1-alpha.4
  ```


## Technical details

A stored cross-site scripting (XSS) vulnerability exists in Parse Server's file upload handler. The default extension blocklist can be bypassed by appending a trailing dot to a filename (e.g., 'malicious.svg.'). This causes the extension parser to return an empty string, bypassing blocklist checks while preserving the attacker-supplied Content-Type. When stored in adapters like S3 or GCS that serve the original Content-Type, the file is delivered as an active type (e.g., image/svg+xml), executing scripts in the victim's browser. The vulnerability is patched in versions 9.9.1-alpha.4 and 8.6.79.

## Affected products

- Parse Community parse-server >= 9.0.0, < 9.9.1-alpha.4; <= 8.6.78

## Identifiers

- CVE-2026-53724
- GHSA-7wqv-xjf3-x35v

## Timeline

- 2026-06-12: advisory: NVD publication date
- 2026-06-19: disclosed: GitHub Advisory published

## References

- [https://api.github.com/users/offset](https://api.github.com/users/offset)
- [https://github.com/offset](https://github.com/offset)
- [https://api.github.com/users/offset/gists%7B/gist_id%7D](https://api.github.com/users/offset/gists%7B/gist_id%7D)
- [https://api.github.com/users/offset/repos](https://api.github.com/users/offset/repos)
- [https://avatars.githubusercontent.com/u/114768995?v=4](https://avatars.githubusercontent.com/u/114768995?v=4)
- [https://api.github.com/users/offset/events%7B/privacy%7D](https://api.github.com/users/offset/events%7B/privacy%7D)

## Related threats

- [Duplicate Advisory: Parse Server vulnerable to stored XSS via malformed Content-Type bypassing file upload extension blocklist](https://junglewise.ai/threats/duplicate-advisory-parse-server-vulnerable-to-stored-xss-via-malformed-00d8867c)
- [Parse Server stored XSS via malformed Content-Type bypass](https://junglewise.ai/threats/cve-2026-61448-parse-server-stored-xss-via-malformed-content-type-bypass)
- [Parse Server information disclosure in LiveQuery ACL transitions](https://junglewise.ai/threats/cve-2026-57481-parse-server-information-disclosure-in-livequery-acl-transitions)
- [Parse Community Parse Server denial of service via nested query operators](https://junglewise.ai/threats/cve-2026-57480-parse-community-parse-server-denial-of-service-via-nested-query)
- [Parse Server stored XSS via file upload extension bypass](https://junglewise.ai/threats/cve-2026-55778-parse-server-stored-xss-via-file-upload-extension-bypass)