GHSA-wpq5-3366-mqw4 is a medium-severity (CVSS 6.1) Cross-site Scripting (XSS) vulnerability in label-studio. 1 public exploit reference exists, so weaponization risk is real. A fix is available for label-studio — see the affected versions and patch details below.
Label Studio allows Cross-Site Scripting (XSS) via GET request to `/projects/upload-example` endpoint
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
Exploitation and automatability from CISA’s SSVC triage for GHSA-wpq5-3366-mqw4.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
GHSA-wpq5-3366-mqw4 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 377,238 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
label-studioReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.
Description
Description
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.
Steps to reproduce
- Create a malicious label config that includes an XSS payload in embedded task data:
<View><!-- {"data": {"text": "<div><img src=x
onerror=eval(atob(`YWxlcnQoIlhTUyIp`))></div>"}} --><HyperText name="text"
value="$text"/></View>
- URL encode the payload and access the following URL:
When executed, the payload causes the application to render an HTML page containing an img tag that fails to load, triggering the onerror event handler which executes base64-decoded JavaScript, demonstrating successful XSS execution in the victim's browser.
Mitigations
- Enable the Content Security Policy in enforcement mode instead of report-only mode to actively block unauthorized script execution
- Deprecate the
GETbehavior at theexample-configendpoint since it's not used
Impact
The vulnerability requires no special privileges and can be exploited by getting a victim to visit a crafted URL. The impact is high as it allows arbitrary JavaScript execution in victims' browsers, potentially exposing sensitive data or enabling account takeover through session theft.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | label-studio | all versions | 1.16.0pip install --upgrade 'label-studio==1.16.0' |
Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for label-studio, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update label-studio to 1.16.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-wpq5-3366-mqw4 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like GHSA-wpq5-3366-mqw4 can be triaged on real exposure rather than presence alone.
Tailored to GHSA-wpq5-3366-mqw4. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
How to detect GHSA-wpq5-3366-mqw4
A community-maintained Nuclei template exists for this CVE. You can scan for it directly:
nuclei -id ghsa-wpq5-3366-mqw4 -u https://target- Template
- Label Studio < 1.16.0 - Cross-Site Scripting
- Severity
- medium
- Impact
- Attackers can execute arbitrary JavaScript in victims' browsers, potentially leading to data theft, session hijacking, or other malicious actions.
- Remediation
- Update to version 1.16.0 or later to patch the vulnerability.
Template by ProjectDiscovery nuclei-templates (0x_Akoko), MIT licensed. View the full template. Scan only systems you are authorised to test.
Frequently Asked Questions
Is GHSA-wpq5-3366-mqw4 in your dependencies?
O3 Security finds GHSA-wpq5-3366-mqw4 across PyPI dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.