Label Studio allows Cross-Site Scripting (XSS) via GET request to /projects/upload-example endpoint

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

6.1 · CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

EPSS

• CVE-2025-25296: 1.90% estimated exploitation activity in the next 30 days; percentile 79.68 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Description Label Studio's /projects/upload-example endpoint allows injection of arbitrary HTML through a GET request with an appropriately crafted labelconfig 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. Steps to reproduce 1. Create a…

Published by the source

14 Feb 2025, 15:23 UTC

Last modified by the source

7 Jul 2026, 17:56 UTC

Source last checked

26 Oct 2026, 13:31 UTC

1. Revision 2 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-wpq5-3366-mqw4

2. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-wpq5-3366-mqw4

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# Patch Next advisory brief: CVE-2025-25296

Advisory: Label Studio allows Cross-Site Scripting (XSS) via GET request to `/projects/upload-example` endpoint
IDs: CVE-2025-25296, GHSA-wpq5-3366-mqw4
Record: https://patchnext.com/advisories/cve-2025-25296 (revision 2, source checked 26 Oct 2026, 13:31 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 6.1)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: label-studio 1.16.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- PyPI label-studio: affected < 1.16.0; fixed in 1.16.0

## Suggested inspection (read-only)
- `python -m pip show label-studio`: prints the installed version. Run with the environment that serves production active.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on label-studio.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://osv.dev/vulnerability/GHSA-wpq5-3366-mqw4 (OSV record GHSA-wpq5-3366-mqw4 lists affected ranges: PyPI label-studio >=0 <1.16.0 (fixed))
- Verified: https://github.com/advisories/GHSA-wpq5-3366-mqw4 (GitHub-reviewed advisory GHSA-wpq5-3366-mqw4 lists affected ranges: PyPI label-studio >=0 <1.16.0)

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