CVE-2026-31868 Parse Server has Stored XSS via file upload of HTML-renderable file types
Attackers can upload malicious SVG or XML files to execute JavaScript in victims' browsers, stealing session tokens or performing actions on their behalf.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2026-31868?
CVE-2026-31868 is a medium-severity cross-site scripting vulnerability in Parseplatform Parse-Server, published on 11 Mar 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Official description
Parse Server is an open source backend that can be deployed to any infrastructure that can run Node.js. Prior to 9.6.0-alpha.4 and 8.6.30, an attacker can upload a file with a file extension or content type that is not blocked by the default configuration of the Parse Server fileUpload.fileExtensions option. The file can contain malicious code, for example JavaScript in an SVG or XHTML file. When the file is accessed via its URL, the browser renders the file and executes the malicious code in the context of the Parse Server domain. This is a stored Cross-Site Scripting (XSS) vulnerability that can be exploited to steal session tokens, redirect users, or perform actions on behalf of other users. Affected file extensions and content types include .svgz, .xht, .xml, .xsl, .xslt, and content types application/xhtml+xml and application/xslt+xml for extensionless uploads. Uploading of .html, .htm, .shtml, .xhtml, and .svg files was already blocked. This vulnerability is fixed in 9.6.0-alpha.4 and 8.6.30.
Weakness: CWE-79
Which versions are affected by CVE-2026-31868?
5 open source packages ship an affected version, including parse-server and parse. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
parse-server npm | All versions | 8.6.30 |
parse-server npm | All versions | 8.6.30 |
parse-server npm | From 9.0.0-alpha.1 | 9.6.0-alpha.4 |
parse-server npm | From 9.0.0-alpha.1 | 9.6.0-alpha.4 |
parse Bitnami | All versions | 8.6.30, 9.6.0 |
Products include Parseplatform Parse-Server.
How do I fix CVE-2026-31868?
Upgrade parse-server to a fixed version for your release line: 8.6.30 or 9.6.0-alpha.4.
Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.
Is CVE-2026-31868 being exploited?
There is no known exploitation of CVE-2026-31868 in the wild and no public exploit code.
Other vulnerabilities in Parseplatform Parse-Server
- CVE-2026-30966 Parse Server role escalation and CLP bypass via direct `_Join` table write
- CVE-2024-27298 Parse Server literalizeRegexPart SQL Injection
- CVE-2022-24760 Command Injection in Parse server
- CVE-2026-30965 Parse Server session token exfiltration via `redirectClassNameForKey` query parameter
- CVE-2023-36475 Parse Server vulnerable to remote code execution via MongoDB BSON parser through prototype pollution
Sources
Also known as BIT-parse-2026-31868, GHSA-v5hf-f4c3-m5rv.