CVE-2025-25296 Label Studio allows Cross-Site Scripting (XSS) via GET request to `/projects/upload-example` endpoint
Attackers can execute arbitrary JavaScript in victims' browsers via a crafted URL, potentially stealing data or hijacking sessions.
- 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-2025-25296?
CVE-2025-25296 is a medium-severity cross-site scripting vulnerability in HumanSignal label-studio, published on 14 Feb 2025. 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
Label Studio is an open source data labeling tool. Prior to version 1.16.0, Label Studio's `/projects/upload-example` endpoint allows injection of arbitrary HTML through a `GET` request with an appropriately crafted `label_config` query parameter. By crafting a specially formatted XML label config with inline task data containing malicious HTML/JavaScript, an attacker can achieve Cross-Site Scripting (XSS). While the application has a Content Security Policy (CSP), it is only set in report-only mode, making it ineffective at preventing script execution. The vulnerability exists because the upload-example endpoint renders user-provided HTML content without proper sanitization on a GET request. This allows attackers to inject and execute arbitrary JavaScript in victims' browsers by getting them to visit a maliciously crafted URL. This is considered vulnerable because it enables attackers to execute JavaScript in victims' contexts, potentially allowing theft of sensitive data, session hijacking, or other malicious actions. Version 1.16.0 contains a patch for the issue.
Weakness: CWE-79
Which versions are affected by CVE-2025-25296?
3 open source packages ship an affected version, including label-studio. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
label-studio PyPI | All versions | 1.16.0 |
label-studio PyPI | All versions | 1.16.0 |
label-studio PyPI | All versions | 1.16.0 |
Products include Humansignal Label Studio.
How do I fix CVE-2025-25296?
Upgrade label-studio to 1.16.0 or later.
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-2025-25296 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2025-25296 exists.
Public exploit code: 1 Nuclei template and 1 proofs of concept on GitHub.
Other vulnerabilities in HumanSignal label-studio
- CVE-2023-43791 Label Studio has Hardcoded Django `SECRET_KEY` that can be Abused to Forge Session Tokens
- CVE-2026-22033 Label Studio vulnerable to full account takeover by chaining Stored XSS + IDOR in User Profile via custom_hotkeys field
- CVE-2025-25297 Label Studio allows Server-Side Request Forgery in the S3 Storage Endpoint
- CVE-2025-47783 label-studio vulnerable to Cross-Site Scripting (Reflected) via the label_config parameter.
- CVE-2023-47117 Object Relational Mapper Leak Vulnerability in Filtering Task in Label Studio
Sources
Also known as GHSA-wpq5-3366-mqw4, PYSEC-2026-1504.