---
title: "Vulnerability Scanning"
description: "Scan container images for known CVEs, surface severity badges in the Resources Hub, and alert on policy violations."
---

Sencho integrates with [Trivy](https://trivy.dev) to scan container images for known vulnerabilities (CVEs), surface severity badges next to your images, and alert when a scan result exceeds a configured threshold. On-demand scanning is available on every tier; automation, policies, and SBOM generation are Skipper and Admiral.

<Frame>
  <img src="/images/vulnerability-scanning/resources-badges.png" alt="Resources Hub showing vulnerability severity badges next to image tags" />
</Frame>

## Prerequisites

The Trivy CLI must be available on the machine running Sencho. Trivy is not bundled with the Sencho Docker image; see [Installing Trivy](/operations/trivy-setup) for mount and installation options. Sencho checks for Trivy on startup and hides scanning UI when the binary is not available.

## Tier availability

| Feature | Community | Skipper | Admiral |
|---------|:---------:|:-------:|:-------:|
| On-demand image scanning | ✓ | ✓ | ✓ |
| Severity badges in the Resources Hub | ✓ | ✓ | ✓ |
| Scan results drawer with vulnerability table | ✓ | ✓ | ✓ |
| Post-deploy automated scanning | ✓ | ✓ | ✓ |
| Scheduled fleet scans (all images on a node) | | ✓ | ✓ |
| Scan policies (warning and critical alerts) | | ✓ | ✓ |
| SBOM generation (SPDX, CycloneDX) | | ✓ | ✓ |
| Scan history and comparison | | ✓ | ✓ |

## On-demand scanning

Navigate to the **Resources** tab and open the **Images** panel. When Trivy is available, every image row shows a shield icon alongside the delete action.

1. Click the shield icon on any image row to start a scan.
2. The row shows a loading spinner while Trivy runs. Most scans finish in 10 to 60 seconds depending on image size and whether the Trivy database is already cached.
3. When the scan completes, a severity badge appears next to the image status (e.g. `CRITICAL`, `HIGH`, `MEDIUM`, `LOW`, or `CLEAN`).
4. Click the badge to open the scan results drawer.

<Frame>
  <img src="/images/vulnerability-scanning/scan-results.png" alt="Vulnerability scan results drawer showing CVE table with severity, package, and fix columns" />
</Frame>

### Reading severity badges

Hovering over a severity badge reveals the breakdown of vulnerabilities by severity and the timestamp of the last scan. The badge color reflects the highest severity found:

| Badge | Meaning |
|-------|---------|
| **CRITICAL** (red) | At least one vulnerability with a CVSS score of 9.0 or higher |
| **HIGH** (amber) | At least one high-severity vulnerability |
| **MEDIUM** (blue) | Only medium and lower vulnerabilities |
| **LOW** (muted) | Only low-severity vulnerabilities |
| **CLEAN** (green) | Scan completed with zero findings |

Scan results are cached by image digest. If the same digest is scanned again within 24 hours, Sencho returns the cached result instantly instead of re-running Trivy.

## The scan results drawer

The drawer shows a full breakdown of the most recent scan for an image:

- **Summary**: counts per severity (critical, high, medium, low), total vulnerabilities, how many have a fix available, the Trivy version used, and when the scan ran.
- **Filter tabs**: narrow the table to a specific severity.
- **Vulnerability table**: paginated list of every CVE found, including:
  - **CVE ID** (linked to the upstream advisory)
  - **Package** name and installed version
  - **Severity** badge
  - **Fixed version** with a green indicator if a fix is available

### Actions

From the drawer header you can:

- **Re-scan**: kick off a fresh scan, ignoring the digest cache.
- **Download SBOM**: export a Software Bill of Materials in SPDX JSON or CycloneDX format (Skipper and Admiral).
- **Export CSV**: export the full vulnerability list for offline review.

## Post-deploy automated scanning

When Trivy is available, Sencho automatically scans every deployed image in the background after a successful deploy. This applies to all deploy paths:

- Stack deploy and redeploy
- Stack update
- Template deploy from the App Store
- Git source apply
- Git source create

The deploy itself is never blocked by scanning; scans run asynchronously and surface their results via the severity badges in the Resources Hub. If high or critical vulnerabilities are found, an alert is dispatched through your configured [notification channels](/features/alerts-notifications).

### Opting out per deployment

The App Store deploy sheet includes an **Scan images for vulnerabilities after deploy** toggle (enabled by default). Uncheck it to skip the post-deploy scan for that single deployment. This does not disable scan policies globally; it simply opts this deployment out of scanning.

<Frame>
  <img src="/images/vulnerability-scanning/app-store-toggle.png" alt="App Store deploy sheet showing the auto-scan checkbox enabled by default" />
</Frame>

## Scheduled fleet scans

<Note>
  Scheduled scans require a **Skipper** or **Admiral** license.
</Note>

You can run recurring scans of every image on a node through the standard [Scheduled Operations](/features/scheduled-operations) system. Create a new scheduled task with action **Scan** and a cron expression. The scheduler iterates every image on the target node with a short delay between scans and records the result in the task's run history.

Use scheduled scans to keep CVE badges fresh even for images that are rarely redeployed: nightly (`0 3 * * *`) is a good default for most fleets.

## Scan policies

<Note>
  Scan policies require a **Skipper** or **Admiral** license.
</Note>

Policies let you define severity thresholds that the post-deploy scanner evaluates against. When a deploy's scan exceeds a policy's threshold, Sencho dispatches an alert. The policy's **Block on deploy** toggle controls the alert severity: warning when off, critical when on.

<Frame>
  <img src="/images/vulnerability-scanning/security-settings.png" alt="Security section of Settings showing the scan policies list with add policy button" />
</Frame>

### Creating a policy

Go to **Settings → Security** and click **Add Policy**.

| Field | Description |
|-------|-------------|
| **Name** | A descriptive label (e.g. "Production critical block"). |
| **Stack pattern** | Optional glob against stack names (e.g. `prod-*`). Leave empty to match every stack. |
| **Max severity** | The threshold. If a scan finds any vulnerability at or above this severity, the policy fires. |
| **Block on deploy** | When enabled, policy violations are dispatched as critical (error) alerts. When disabled, they are dispatched as warnings. |
| **Enabled** | Disabled policies are skipped during evaluation. |

### Policy scoping

When multiple policies match a deploy, Sencho picks the most specific one:

1. Policies scoped to a specific node win over global policies.
2. Policies with a stack pattern win over wildcard policies.
3. Disabled policies are never applied.

Only one policy is evaluated per deploy; use a single tight pattern rather than overlapping policies for clarity.

## SBOM generation

<Note>
  SBOM generation requires a **Skipper** or **Admiral** license.
</Note>

A Software Bill of Materials (SBOM) is a machine-readable inventory of every package present in a container image. SBOMs are required by an increasing number of security frameworks (SLSA, Executive Order 14028, EU Cyber Resilience Act) and are useful for offline compliance reviews.

From the scan results drawer, click **Download SBOM** and choose a format:

| Format | Use case |
|--------|----------|
| **SPDX JSON** | Widely supported, best for tooling integration. |
| **CycloneDX** | Richer dependency metadata, better for supply-chain analysis. |

The download starts immediately and uses the image's digest (when available) in the filename.

## Scan history

Every scan Sencho runs is stored with its full vulnerability detail. Scan records are automatically pruned after 90 days to keep the database compact. The history is used to power:

- **Digest caching**: skip re-scanning an image that has already been scanned within 24 hours.
- **Trend badges**: surface whether the latest scan added or resolved vulnerabilities compared to the previous scan for the same image.

## How it works

1. On startup, Sencho looks for the `trivy` binary on `PATH` and caches its availability.
2. When a scan is triggered, Sencho resolves the image digest via Docker and checks the 24-hour cache. If a completed scan exists for that digest, it is returned instantly.
3. Otherwise, Sencho spawns `trivy image --format json --quiet <image-ref>` and parses the JSON output into the vulnerability database.
4. Private registry credentials are forwarded automatically by writing a temporary `DOCKER_CONFIG` for the Trivy subprocess, then deleting it when the scan completes.
5. Scan status, counts per severity, and the full vulnerability list are persisted for display in the drawer and for policy evaluation.

## Troubleshooting

### Scan button is not visible

Sencho hides scanning UI when the Trivy binary is not detected. Check **Settings → Support** for the Trivy availability status, then follow [Installing Trivy](/operations/trivy-setup) if it is missing.

### Scans time out

The default scan timeout is 5 minutes. Very large images (2+ GB) over a slow connection may exceed this; pre-pulling the image to the host speeds up the scan significantly because Trivy works against the local image store.

### Private registry images fail to scan

Sencho forwards the same registry credentials configured under **Settings → Registries** to Trivy during a scan. If a pull works in Sencho but a scan fails, make sure the image has been pulled at least once (Trivy can then work against the cached local image).

### Badge is out of date after an image update

Post-deploy scanning only runs on deploy actions. For long-running images that aren't redeployed, schedule a recurring scan (Skipper+) or click the shield icon in the Resources Hub to re-scan on demand.
