---
title: CVE Severity Re-Ranker API
emoji: 🛡️
colorFrom: blue
colorTo: indigo
sdk: docker
app_port: 7860
pinned: false
---

# CVE Vulnerability Severity Re-Ranking

> Context-aware vulnerability prioritisation using NLP, Deep Learning, and Machine Learning

[![Python](https://img.shields.io/badge/Python-3.10-blue?style=flat-square)](https://python.org)
[![Next.js](https://img.shields.io/badge/Next.js-Frontend-black?style=flat-square)](https://nextjs.org)
[![FastAPI](https://img.shields.io/badge/FastAPI-Backend-teal?style=flat-square)](https://fastapi.tiangolo.com)
[![XGBoost](https://img.shields.io/badge/XGBoost-3.2-orange?style=flat-square)](https://xgboost.readthedocs.io)
[![SecBERT](https://img.shields.io/badge/SecBERT-BERT--base-purple?style=flat-square)](https://huggingface.co/jackaduma/SecBERT)
[![NVD](https://img.shields.io/badge/Dataset-NVD%20200k%2B%20CVEs-green?style=flat-square)](https://nvd.nist.gov)
[![SDG](https://img.shields.io/badge/SDG-9%20%26%2016-teal?style=flat-square)](https://sdgs.un.org/goals)

---

## The Problem

The [National Vulnerability Database (NVD)](https://nvd.nist.gov) publishes thousands of CVEs every month, each with a static CVSS score. Security teams sort by CVSS and start patching from the top — but CVSS is environment-blind. A CVSS 9.8 Critical in software you don't use is less urgent than a CVSS 7.5 High in software running on your public-facing server.

This project fixes that.

---

## What This System Does

1. Analyses CVE descriptions from the NVD using NLP + SecBERT embeddings
2. Predicts severity (Low / Medium / High / Critical) using XGBoost
3. Re-ranks CVEs based on your specific software inventory
4. Surfaces the most dangerous vulnerabilities for **your environment** — not a generic list
5. Serves results through a FastAPI backend consumed by a Next.js dashboard

---

## Team

| Name | Roll No | Contribution |
|---|---|---|
| Manglam Jaiswal | 10127 | Data collection, NLP preprocessing, EDA |
| Tanaya Bane | 10107 | Re-ranking module, Next.js UI, evaluation |
| Tanmay Sarode | 10154 | SecBERT embeddings, XGBoost training, SHAP |

Third Year | Semester 6 | ML + DL + NLP Mini Project | 2025–26

---

## Results

| Metric | Value |
|---|---|
| Dataset | 200,431 CVEs (NVD 2019–2026) |
| Model | XGBoost on 781-dim fused feature vector |
| Weighted F1 | **0.77** |
| Accuracy | **77%** |
| Medium F1 | 0.82 |
| Critical F1 | 0.73 |

---

## System Architecture

```
NVD API
   │
   ▼
[Layer 1 — NLP]
  Text cleaning → spaCy NER → keyword feature flags
   │
   ▼
[Layer 2 — Deep Learning]
  SecBERT → 768-dim CLS embedding per CVE
   │
   ▼
[Layer 3 — Feature Fusion]
  BERT (768) + NLP features (8) + CVSS metadata (5) = 781-dim vector
   │
   ▼
[Layer 4 — Machine Learning]
  XGBoost classifier → Low / Medium / High / Critical
   │
   ▼
[Layer 5 — Contextual Re-Ranking]
  User inventory CSV → fuzzy match → boost score → re-sorted list
   │
   ▼
[FastAPI Backend]
  REST API serving predictions and re-ranked results
   │
   ▼
[Next.js Frontend]
  Single CVE lookup | Bulk CSV upload | Inventory matcher | Dashboard
```

---

## SDG Mapping

**SDG 9 — Industry, Innovation and Infrastructure**
Makes intelligent vulnerability prioritisation accessible to organisations of all sizes.

**SDG 16 — Peace, Justice and Strong Institutions**
Strengthens institutional resilience against cyberattacks by enabling faster, targeted vulnerability response.

---

## Repository Structure

```
cve-severity-reranker/
│
├── .github/
│   └── workflows/
│       ├── daily_fetch.yml         # Fetches new CVEs every day at 6 AM UTC
│       └── weekly_pipeline.yml     # Full pipeline every Sunday at 2 AM UTC
│
├── scripts/
│   ├── 01_fetch.py                 # NVD API data collection
│   ├── 02_preprocess.py            # NLP cleaning + feature engineering
│   ├── 03_embeddings.py            # SecBERT embedding generation
│   └── 04_train.py                 # XGBoost training (smart update mode)
│
├── backend/
│   ├── main.py                     # FastAPI app — all API routes
│   ├── pipeline.py                 # Prediction + re-ranking logic
│   ├── reranker.py                 # Inventory matching + boost formula
│   └── requirements.txt            # Python dependencies for backend
│
├── frontend/
│   ├── app/                        # Next.js app directory
│   │   ├── page.tsx                # Home — dashboard overview
│   │   ├── lookup/page.tsx         # Single CVE lookup screen
│   │   ├── bulk/page.tsx           # Bulk CSV upload screen
│   │   └── inventory/page.tsx      # Inventory matcher screen
│   ├── components/                 # Reusable React components
│   ├── public/                     # Static assets
│   ├── package.json
│   └── next.config.js
│
├── data/
│   ├── cves_raw.csv                # Raw NVD data (Git LFS)
│   ├── cves_processed.csv          # Cleaned + feature engineered (Git LFS)
│   ├── bert_embeddings.npy         # 200k × 768 embedding matrix (Git LFS)
│   └── last_updated.json           # Tracks last data collection date
│
├── models/
│   ├── model_xgb.pkl               # Trained XGBoost model (Git LFS)
│   ├── label_encoder.pkl           # Label encoder
│   └── training_tracker.json       # Tracks rows model was trained on
│
├── notebooks/
│   ├── 01_data_collection.ipynb
│   ├── 02_preprocessing.ipynb
│   ├── 04_embeddings.ipynb
│   ├── 05_training.ipynb
│   └── 06_live_updater.ipynb
│
├── requirements.txt
└── README.md
```

---

## Quick Start

### Prerequisites

- Python 3.10+
- Node.js 18+
- npm or yarn

### 1. Clone the repo

```bash
git clone https://github.com/ManglamX/cve-severity-reranker.git
cd cve-severity-reranker
```

### 2. Start the FastAPI backend

```bash
cd backend
pip install -r requirements.txt
python -m spacy download en_core_web_sm
uvicorn main:app --reload --port 8000
```

Backend runs at `http://localhost:8000`
Interactive API docs at `http://localhost:8000/docs`

### 3. Start the Next.js frontend

```bash
cd frontend
npm install
npm run dev
```

Frontend runs at `http://localhost:3000`

---

## API Endpoints

| Method | Endpoint | Description |
|---|---|---|
| `GET` | `/health` | Health check |
| `GET` | `/cve/{cve_id}` | Analyse a single CVE |
| `POST` | `/bulk` | Analyse a list of CVE IDs |
| `POST` | `/inventory` | Find CVEs matching uploaded inventory |
| `GET` | `/stats` | Dataset and model statistics |

### Example — single CVE

```bash
curl http://localhost:8000/cve/CVE-2021-44228
```

```json
{
  "cve_id": "CVE-2021-44228",
  "cvss_score": 10.0,
  "cvss_label": "Critical",
  "predicted_label": "Critical",
  "context_score": 0.512,
  "boost_factor": 1.0,
  "matched_inventory": [],
  "attack_vector": "NETWORK",
  "has_remote": 1,
  "has_exec": 1
}
```

### Example — bulk with inventory

```bash
curl -X POST http://localhost:8000/bulk \
  -H "Content-Type: application/json" \
  -d '{
    "cve_ids": ["CVE-2021-44228", "CVE-2022-30190"],
    "inventory": ["Apache Log4j", "OpenSSL", "Windows Server"]
  }'
```

---

## Frontend Screens

### Dashboard
Overview of your CVE dataset — class distribution chart, top 10 highest context score CVEs, model performance summary.

### Single CVE Lookup
Enter any CVE ID and get instant analysis — predicted severity, context score, risk signals (remote exploitable, code execution, attack vector), and inventory match warning if applicable.

### Bulk CSV Upload
Upload a CSV with a `cve_id` column. Get back a ranked table sorted by context score. Download results as CSV.

### Inventory Matcher
Upload your software inventory CSV. The system returns only CVEs that affect your software, ranked by context score.

**Sample inventory CSV format:**
```csv
software
Apache HTTP Server
OpenSSL
Windows Server
MySQL
Log4j
nginx
```

---

## How the Re-Ranking Works

```
boost = 1.0
  + 0.30 × (number of inventory matches)
  × 1.25  (if public exploit exists)
  × 1.15  (if remote + unauthenticated)
  × 1.10  (if attack vector = NETWORK)

context_score = min(prob_critical × boost, 1.0)
```

CVEs are sorted by `context_score` — not by CVSS score.

**Example — CVE-2021-44228 (Log4Shell)**

| Condition | Context Score |
|---|---|
| No inventory | 0.51 |
| Inventory contains `Log4j` | 0.67 (boost 1.43×) |

---

## Automation (GitHub Actions)

| Workflow | Schedule | What it does |
|---|---|---|
| `daily_fetch.yml` | Every day 6 AM UTC | Fetches new CVEs, updates `cves_raw.csv` |
| `weekly_pipeline.yml` | Every Sunday 2 AM UTC | Fetch → preprocess → embed → retrain |

Smart training — only does what is needed:

| Situation | Mode | Time |
|---|---|---|
| Dataset unchanged | Skip — loads existing model | 10 sec |
| < 10% new rows | Update — trains on new rows only | ~2 min |
| ≥ 10% new rows | Full retrain | ~15 min |

Add your NVD API key as a GitHub Secret named `NVD_API_KEY` to enable automation.

---

## Retraining (Google Colab)

1. `notebooks/01_data_collection.ipynb` — fetch CVE data
2. `notebooks/02_preprocessing.ipynb` — NLP pipeline
3. `notebooks/04_embeddings.ipynb` — SecBERT embeddings (GPU, ~65 min)
4. `notebooks/05_training.ipynb` — XGBoost training + evaluation

Each notebook is smart — skips completed steps and only processes new rows.

---

## Tech Stack

| Component | Technology |
|---|---|
| Frontend | Next.js (React) |
| Backend | FastAPI (Python) |
| NLP | spaCy, regex |
| Deep Learning | SecBERT, PyTorch, Hugging Face transformers |
| Machine Learning | XGBoost, scikit-learn |
| Explainability | SHAP TreeExplainer |
| Inventory matching | FuzzyWuzzy |
| Data source | NVD REST API v2.0 |
| Training platform | Google Colab (T4 GPU) |
| Automation | GitHub Actions |
| Storage | Google Drive + Git LFS |

---

## Evaluation

**Classification Report — test set (40,087 CVEs)**

| Class | Precision | Recall | F1 | Support |
|---|---|---|---|---|
| Critical | 0.72 | 0.74 | 0.73 | 4,705 |
| High | 0.76 | 0.72 | 0.74 | 14,792 |
| Low | 0.88 | 0.38 | 0.53 | 1,589 |
| Medium | 0.79 | 0.86 | 0.82 | 19,001 |
| **Weighted avg** | **0.77** | **0.77** | **0.77** | **40,087** |

Low class recall is lower due to class imbalance. Planned fix: SMOTE oversampling.

---

## Dataset

| Property | Value |
|---|---|
| Source | NVD REST API v2.0 |
| Date range | January 2019 — March 2026 |
| Total CVEs | 200,431 |
| Features per CVE | 781 (768 BERT + 8 NLP + 5 metadata) |
| Auto-updated | Daily via GitHub Actions |

**CVSS label mapping:**

| Score | Label |
|---|---|
| 0.0 – 3.9 | Low |
| 4.0 – 6.9 | Medium |
| 7.0 – 8.9 | High |
| 9.0 – 10.0 | Critical |

---

## References

1. Shahid & Debar. *CVSS-BERT.* arXiv 2021.
2. *NLP-Based Analysis of Cyber Threats.* PMC 2023.
3. *CVE Severity Prediction — A Deep Learning Approach.* ScienceDirect 2024.
4. jackaduma. *SecBERT.* Hugging Face Hub.
5. Lundberg & Lee. *SHAP.* NeurIPS 2017.
6. Chen & Guestrin. *XGBoost.* KDD 2016.

---

## License

This project was built for academic purposes as part of a Third Year Mini Project (2025–26).