CVE-2026-76073 — Label Studio does not scope the annotation detail endpoint to the requesting user's…¶

Key facts

CVE-2026-76073 is a High (8.8) vulnerability: Label Studio does not scope the annotation detail endpoint to the requesting user's…. This entry ships a detection-only PoC and a Docker test lab.


CVE	CVE-2026-76073
Severity	High (8.8)
Detection / prevention	—
PoC	poc.py
Source	2026/CVE-2026-76073/

Details¶

English | 한국어

Description¶

Label Studio does not scope the annotation detail endpoint to the requesting user's organization. AnnotationAPI in label_studio/tasks/api.py declares queryset = Annotation.objects.all() and provides no get_queryset override, so the default lookup retrieves any annotation by primary key. The view's permission_required entries name annotations.view, annotations.change and annotations.delete, and label_studio/core/permissions.py registers every permission with rules.is_authenticated, so the check is satisfied by any logged-in account and no object-level organization test runs. The sibling task endpoint does constrain its queryset with project__organization set to the requester's active organization, which is the boundary this path omits. Annotation identifiers are sequential integers, so an authenticated user of one organization can enumerate identifiers to read, modify and delete annotations belonging to other organizations on the same instance. The same unscoped queryset appears on AnnotationConvertAPI in the same file.

Vulnerability Details¶

Property	Value
CVE ID	CVE-2026-76073
Type	IDOR
CVSS Score	8.8

Proof of Concept¶

Download¶

# Download PoC script
curl -O https://raw.githubusercontent.com/fankh/vulnerability-poc/main/2026/CVE-2026-76073/poc.py

Usage¶

# Run PoC against target
python3 poc.py --target <TARGET_URL>

# With authentication
python3 poc.py --target <TARGET_URL> --username <USER> --password <PASS>

⚠️ Warning: This PoC is for authorized security testing only. It uses detection-only techniques and does not exploit or damage target systems.

Test Lab¶

This repository includes a Docker-based test environment with both vulnerable and patched applications.

Quick Start¶

# Clone and navigate to CVE directory
cd CVE-2026-76073

# Start both applications
docker-compose up -d

# Run tests
./run-tests.sh    # Linux/Mac
./run-tests.ps1   # Windows PowerShell

Application Endpoints¶

Application	URL	Status
Vulnerable App	http://localhost:8080	Shows vulnerability
Patched App	http://localhost:8081	Demonstrates fix

Directory Structure¶

├── README.md           # English documentation
├── README_KO.md        # Korean documentation
├── poc.py              # PoC detection script
├── docker-compose.yml  # Container orchestration
├── run-tests.sh        # Linux/Mac test runner
├── run-tests.ps1       # Windows test runner
├── vulnerable-app/     # Vulnerable version
│   ├── app.py
│   ├── Dockerfile
│   └── requirements.txt
└── patched-app/        # Fixed version
    ├── app.py
    ├── Dockerfile
    └── requirements.txt

References¶

https://github.com/HumanSignal/label-studio
https://github.com/HumanSignal/label-studio/blob/1.23.0/label_studio/tasks/api.py
https://github.com/HumanSignal/label-studio/issues/9796
https://www.vulncheck.com/advisories/label-studio-through-cross-organization-annotation-access-via-unscoped-annotationapi-queryset

Generated by PoC Generator on 2026-08-25T06:40:44.966413682

Frequently asked questions¶

What is CVE-2026-76073?¶

CVE-2026-76073 is a High (8.8) vulnerability: Label Studio does not scope the annotation detail endpoint to the requesting user's…. This entry ships a detection-only PoC and a Docker test lab.

How do I detect CVE-2026-76073?¶

Run the detection-only PoC included with this entry against your Docker test lab to confirm whether a target is affected; pair it with your own IDS logging.

How do I block or mitigate CVE-2026-76073?¶

Upgrade to a fixed version per the vendor advisory; the NVD record lists the affected versions. Use the included PoC to verify your remediation.

For authorized security testing and research only. See the full source and NVD record.