Mostly safe — a couple of notes worth reading.
Scanned 5/3/2026, 7:38:41 PM·Cached result·Fast Scan·88 rules·How we decide ↗
AIVSS Score
Low
Severity Breakdown
0
critical
0
high
17
medium
0
low
MCP Server Information
Findings
This package has a security grade of B and a safety score of 84/100, indicating a moderate level of risk. It contains 17 medium-severity issues, primarily related to server configuration and resource exhaustion, which could potentially lead to performance degradation or security vulnerabilities if not addressed. While there are no critical or high-severity findings, the presence of multiple medium issues warrants careful consideration before installation.
No known CVEs found for this package or its dependencies.
Scan Details
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Fast scan found 17 findings using rule-based analysis. Upgrade for LLM consensus across 5 judges, AI-generated remediation, and cross-file taint analysis.
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17 of 17 findings
17 findings
Network / IO / subprocess call without an explicit timeout. A malicious or hung upstream (HTTP host, socket peer, child process) can pin threads, exhaust connection/process pools, and make the MCP server unresponsive. Always pass a bounded timeout. v2 extends v1 with subprocess coverage (R03 from the legacy readiness audit).
Evidence
| 1 | # Slack MCP Server |
| 2 | [](https://archestra.ai/mcp-catalog/korotovsky__slack-mcp-server) |
| 3 | |
| 4 | Model Context Protocol (MCP) server for Slack Workspaces. The most powerful MCP Slack server — supports Stdio, SSE and HTTP transports, proxy settings, DMs, Group DMs, Smart History fetch (by date or count), may work via OAuth or in complete stealth mode with no permissions and scopes in Workspace 😏. |
| 5 | |
| 6 | > [!IMPORTANT] |
| 7 |
Remediation
Pass timeout= on every call: - HTTP: `requests.get(url, timeout=5)`, `httpx.get(url, timeout=5.0)` - Node fetch: `AbortSignal.timeout(5000)` - Subprocess: `subprocess.run(["cmd"], timeout=30, check=True)` Pick a value short enough to fail fast and retry.
Network / IO / subprocess call without an explicit timeout. A malicious or hung upstream (HTTP host, socket peer, child process) can pin threads, exhaust connection/process pools, and make the MCP server unresponsive. Always pass a bounded timeout. v2 extends v1 with subprocess coverage (R03 from the legacy readiness audit).
Evidence
| 4 | "display_name": "Slack MCP Server", |
| 5 | "version": "0.0.0", |
| 6 | "description": "The most powerful MCP Slack Server with no permission requirements, Apps support, multiple transports Stdio and SSE, DMs, Group DMs and smart history fetch logic.", |
| 7 | "long_description": "Model Context Protocol (MCP) server for Slack Workspaces. The most powerful MCP Slack server — supports Stdio and SSE transports, proxy settings, DMs, Group DMs, Smart History fetch (by date or count), may work via OAuth or in complete |
Remediation
Pass timeout= on every call: - HTTP: `requests.get(url, timeout=5)`, `httpx.get(url, timeout=5.0)` - Node fetch: `AbortSignal.timeout(5000)` - Subprocess: `subprocess.run(["cmd"], timeout=30, check=True)` Pick a value short enough to fail fast and retry.
Dockerfile never sets a non-root `USER` directive, so the CMD runs as root by default. Any RCE or library-level vulnerability exploited inside this container gets full privileges (MCP Top-10 R3). Add `USER <non-root>` before CMD / ENTRYPOINT in the final stage — e.g. `USER 1000`, `USER nobody`, or `USER nonroot` on distroless.
Evidence
| 1 | FROM golang:1.24 AS build |
| 2 | |
| 3 | ENV CGO_ENABLED=0 |
| 4 | ENV GOTOOLCHAIN=local |
| 5 | ENV GOCACHE=/go/pkg/mod |
| 6 | |
| 7 | RUN apt-get update \ |
| 8 | && apt-get install -y --no-install-recommends net-tools curl |
| 9 | |
| 10 | WORKDIR /app |
| 11 | |
| 12 | COPY go.mod go.sum ./ |
| 13 | |
| 14 | RUN --mount=type=cache,target=/go/pkg/mod go mod download |
| 15 | |
| 16 | COPY . /app |
| 17 | |
| 18 | RUN --mount=type=cache,target=/go/pkg/mod \ |
| 19 | go build -ldflags="-s -w" -o /go/bin/mcp-server ./cmd/slack-mcp-server |
| 20 | |
| 21 | FROM build AS dev |
| 22 | |
| 23 | RUN --mount=type=cache,target=/go/pkg/mod \ |
| 24 | go install github.com/go-d |
Remediation
Create and switch to a non-root user before the CMD / ENTRYPOINT: RUN adduser --system --uid 1000 app USER 1000 Or reuse the base image's shipped non-root account (e.g. `USER nobody`, `USER nonroot` on distroless). Multi-stage builds only need the USER directive in the final stage.
MCP manifest declares tools but no authentication field is present (none of: auth, authorization, bearer, oauth, mtls, apiKey, api_key, basic, token, authToken). Absence is a weak signal — confirm whether the server relies on network-layer or host-level auth, or declare the real mechanism explicitly so reviewers can audit it.
Evidence
| 1 | ## 3. Configuration and Usage |
| 2 | |
| 3 | > **Maintainer note** |
| 4 | > |
| 5 | > I’m currently seeking a new **full-time or contract engineering role** after losing my primary job. |
| 6 | > This directly impacts my ability to maintain this project long-term. |
| 7 | > |
| 8 | > If you know a **Hiring Manager, Engineering Manager, or startup team** that might be a good fit, I’d be grateful for an introduction. |
| 9 | > |
| 10 | > 👉 See the full context in **[this issue](https://github.com/korotovsky/slack-mcp-server/issues/150)** |
| 11 | > 📩 Contact: `dmitry@kor |
Remediation
Declare a real authentication mechanism in the manifest, matching what the running server actually enforces: - `"auth": "bearer"` with a token scheme documented for callers - `"auth": "oauth"` / `"oauth2": { ... }` for delegated flows - `"apiKey": { "header": "X-API-Key", "prefix": "..." }` - `"mtls": true` when client certificates are required If the server is intentionally unauthenticated (stdio-only, local developer tool, trusted-host network), document the assumption in the manifest via a `"
GitHub Actions `uses:` reference is not pinned to a 40-character commit SHA. Tags (`@v4`) and branches (`@main`) are mutable — a compromised maintainer or a tag rewrite can substitute malicious code into your CI pipeline silently. Pin to a SHA: `uses: actions/checkout@8e5e7e5ab8b370d6c329ec480221332ada57f0ab`. For readability, include the version as a trailing comment: `# v4.1.1`. Tools like `pinact` / `ratchet` automate this. Allowed unpinned forms (excluded by the rule): - Local actions `.
Evidence
| 15 | runs-on: ubuntu-latest |
| 16 | steps: |
| 17 | - name: Checkout code |
| 18 | uses: actions/checkout@v6 |
| 19 | |
| 20 | - name: Set up QEMU |
| 21 | uses: docker/setup-qemu-action@v3 |
Remediation
Pin every `uses:` to a 40-character commit SHA. Trailing comment with the version helps reviewers: `uses: actions/checkout@8e5e7e5ab8b370d6c329ec480221332ada57f0ab # v4.1.1` Automate the migration with `pinact` (https://github.com/suzuki-shunsuke/pinact) or `ratchet` (https://github.com/sethvargo/ratchet). Add a `pinact run --check` pre-commit hook so future PRs stay pinned. Re-pin when the action releases a new version — Dependabot can do this automatically with `version-update-strategy: inc
GitHub Actions `uses:` reference is not pinned to a 40-character commit SHA. Tags (`@v4`) and branches (`@main`) are mutable — a compromised maintainer or a tag rewrite can substitute malicious code into your CI pipeline silently. Pin to a SHA: `uses: actions/checkout@8e5e7e5ab8b370d6c329ec480221332ada57f0ab`. For readability, include the version as a trailing comment: `# v4.1.1`. Tools like `pinact` / `ratchet` automate this. Allowed unpinned forms (excluded by the rule): - Local actions `.
Evidence
| 18 | uses: actions/checkout@v6 |
| 19 | |
| 20 | - name: Set up Go |
| 21 | uses: actions/setup-go@v6 |
| 22 | with: |
| 23 | go-version-file: "go.mod" |
Remediation
Pin every `uses:` to a 40-character commit SHA. Trailing comment with the version helps reviewers: `uses: actions/checkout@8e5e7e5ab8b370d6c329ec480221332ada57f0ab # v4.1.1` Automate the migration with `pinact` (https://github.com/suzuki-shunsuke/pinact) or `ratchet` (https://github.com/sethvargo/ratchet). Add a `pinact run --check` pre-commit hook so future PRs stay pinned. Re-pin when the action releases a new version — Dependabot can do this automatically with `version-update-strategy: inc
GitHub Actions `uses:` reference is not pinned to a 40-character commit SHA. Tags (`@v4`) and branches (`@main`) are mutable — a compromised maintainer or a tag rewrite can substitute malicious code into your CI pipeline silently. Pin to a SHA: `uses: actions/checkout@8e5e7e5ab8b370d6c329ec480221332ada57f0ab`. For readability, include the version as a trailing comment: `# v4.1.1`. Tools like `pinact` / `ratchet` automate this. Allowed unpinned forms (excluded by the rule): - Local actions `.
Evidence
| 39 | run: make build-dxt |
| 40 | |
| 41 | - name: Upload artifacts |
| 42 | uses: softprops/action-gh-release@v2 |
| 43 | with: |
| 44 | generate_release_notes: true |
| 45 | make_latest: true |
Remediation
Pin every `uses:` to a 40-character commit SHA. Trailing comment with the version helps reviewers: `uses: actions/checkout@8e5e7e5ab8b370d6c329ec480221332ada57f0ab # v4.1.1` Automate the migration with `pinact` (https://github.com/suzuki-shunsuke/pinact) or `ratchet` (https://github.com/sethvargo/ratchet). Add a `pinact run --check` pre-commit hook so future PRs stay pinned. Re-pin when the action releases a new version — Dependabot can do this automatically with `version-update-strategy: inc
GitHub Actions `uses:` reference is not pinned to a 40-character commit SHA. Tags (`@v4`) and branches (`@main`) are mutable — a compromised maintainer or a tag rewrite can substitute malicious code into your CI pipeline silently. Pin to a SHA: `uses: actions/checkout@8e5e7e5ab8b370d6c329ec480221332ada57f0ab`. For readability, include the version as a trailing comment: `# v4.1.1`. Tools like `pinact` / `ratchet` automate this. Allowed unpinned forms (excluded by the rule): - Local actions `.
Evidence
| 27 | id: buildx |
| 28 | |
| 29 | - name: Login to GitHub Container Registry |
| 30 | uses: docker/login-action@v3 |
| 31 | with: |
| 32 | registry: ghcr.io |
| 33 | username: ${{ github.actor }} |
Remediation
Pin every `uses:` to a 40-character commit SHA. Trailing comment with the version helps reviewers: `uses: actions/checkout@8e5e7e5ab8b370d6c329ec480221332ada57f0ab # v4.1.1` Automate the migration with `pinact` (https://github.com/suzuki-shunsuke/pinact) or `ratchet` (https://github.com/sethvargo/ratchet). Add a `pinact run --check` pre-commit hook so future PRs stay pinned. Re-pin when the action releases a new version — Dependabot can do this automatically with `version-update-strategy: inc
GitHub Actions `uses:` reference is not pinned to a 40-character commit SHA. Tags (`@v4`) and branches (`@main`) are mutable — a compromised maintainer or a tag rewrite can substitute malicious code into your CI pipeline silently. Pin to a SHA: `uses: actions/checkout@8e5e7e5ab8b370d6c329ec480221332ada57f0ab`. For readability, include the version as a trailing comment: `# v4.1.1`. Tools like `pinact` / `ratchet` automate this. Allowed unpinned forms (excluded by the rule): - Local actions `.
Evidence
| 25 | - name: Checkout |
| 26 | uses: actions/checkout@v6 |
| 27 | |
| 28 | - uses: actions/setup-go@v6 |
| 29 | with: |
| 30 | go-version: ${{ env.GO_VERSION }} |
Remediation
Pin every `uses:` to a 40-character commit SHA. Trailing comment with the version helps reviewers: `uses: actions/checkout@8e5e7e5ab8b370d6c329ec480221332ada57f0ab # v4.1.1` Automate the migration with `pinact` (https://github.com/suzuki-shunsuke/pinact) or `ratchet` (https://github.com/sethvargo/ratchet). Add a `pinact run --check` pre-commit hook so future PRs stay pinned. Re-pin when the action releases a new version — Dependabot can do this automatically with `version-update-strategy: inc
GitHub Actions `uses:` reference is not pinned to a 40-character commit SHA. Tags (`@v4`) and branches (`@main`) are mutable — a compromised maintainer or a tag rewrite can substitute malicious code into your CI pipeline silently. Pin to a SHA: `uses: actions/checkout@8e5e7e5ab8b370d6c329ec480221332ada57f0ab`. For readability, include the version as a trailing comment: `# v4.1.1`. Tools like `pinact` / `ratchet` automate this. Allowed unpinned forms (excluded by the rule): - Local actions `.
Evidence
| 15 | steps: |
| 16 | - name: Checkout |
| 17 | uses: actions/checkout@v6 |
| 18 | |
| 19 | - name: Set up Go |
| 20 | uses: actions/setup-go@v6 |
Remediation
Pin every `uses:` to a 40-character commit SHA. Trailing comment with the version helps reviewers: `uses: actions/checkout@8e5e7e5ab8b370d6c329ec480221332ada57f0ab # v4.1.1` Automate the migration with `pinact` (https://github.com/suzuki-shunsuke/pinact) or `ratchet` (https://github.com/sethvargo/ratchet). Add a `pinact run --check` pre-commit hook so future PRs stay pinned. Re-pin when the action releases a new version — Dependabot can do this automatically with `version-update-strategy: inc
GitHub Actions `uses:` reference is not pinned to a 40-character commit SHA. Tags (`@v4`) and branches (`@main`) are mutable — a compromised maintainer or a tag rewrite can substitute malicious code into your CI pipeline silently. Pin to a SHA: `uses: actions/checkout@8e5e7e5ab8b370d6c329ec480221332ada57f0ab`. For readability, include the version as a trailing comment: `# v4.1.1`. Tools like `pinact` / `ratchet` automate this. Allowed unpinned forms (excluded by the rule): - Local actions `.
Evidence
| 18 | uses: actions/checkout@v6 |
| 19 | |
| 20 | - name: Set up QEMU |
| 21 | uses: docker/setup-qemu-action@v3 |
| 22 | with: |
| 23 | platforms: all |
Remediation
Pin every `uses:` to a 40-character commit SHA. Trailing comment with the version helps reviewers: `uses: actions/checkout@8e5e7e5ab8b370d6c329ec480221332ada57f0ab # v4.1.1` Automate the migration with `pinact` (https://github.com/suzuki-shunsuke/pinact) or `ratchet` (https://github.com/sethvargo/ratchet). Add a `pinact run --check` pre-commit hook so future PRs stay pinned. Re-pin when the action releases a new version — Dependabot can do this automatically with `version-update-strategy: inc
GitHub Actions `uses:` reference is not pinned to a 40-character commit SHA. Tags (`@v4`) and branches (`@main`) are mutable — a compromised maintainer or a tag rewrite can substitute malicious code into your CI pipeline silently. Pin to a SHA: `uses: actions/checkout@8e5e7e5ab8b370d6c329ec480221332ada57f0ab`. For readability, include the version as a trailing comment: `# v4.1.1`. Tools like `pinact` / `ratchet` automate this. Allowed unpinned forms (excluded by the rule): - Local actions `.
Evidence
| 16 | runs-on: ubuntu-latest |
| 17 | steps: |
| 18 | - name: Checkout |
| 19 | uses: actions/checkout@v6.0.1 |
| 20 | |
| 21 | - name: Run Trivy (Go dependencies) |
| 22 | uses: aquasecurity/trivy-action@0.34.0 |
Remediation
Pin every `uses:` to a 40-character commit SHA. Trailing comment with the version helps reviewers: `uses: actions/checkout@8e5e7e5ab8b370d6c329ec480221332ada57f0ab # v4.1.1` Automate the migration with `pinact` (https://github.com/suzuki-shunsuke/pinact) or `ratchet` (https://github.com/sethvargo/ratchet). Add a `pinact run --check` pre-commit hook so future PRs stay pinned. Re-pin when the action releases a new version — Dependabot can do this automatically with `version-update-strategy: inc
GitHub Actions `uses:` reference is not pinned to a 40-character commit SHA. Tags (`@v4`) and branches (`@main`) are mutable — a compromised maintainer or a tag rewrite can substitute malicious code into your CI pipeline silently. Pin to a SHA: `uses: actions/checkout@8e5e7e5ab8b370d6c329ec480221332ada57f0ab`. For readability, include the version as a trailing comment: `# v4.1.1`. Tools like `pinact` / `ratchet` automate this. Allowed unpinned forms (excluded by the rule): - Local actions `.
Evidence
| 18 | uses: actions/checkout@v6 |
| 19 | |
| 20 | - name: Set up Go |
| 21 | uses: actions/setup-go@v6 |
| 22 | with: |
| 23 | go-version-file: "go.mod" |
Remediation
Pin every `uses:` to a 40-character commit SHA. Trailing comment with the version helps reviewers: `uses: actions/checkout@8e5e7e5ab8b370d6c329ec480221332ada57f0ab # v4.1.1` Automate the migration with `pinact` (https://github.com/suzuki-shunsuke/pinact) or `ratchet` (https://github.com/sethvargo/ratchet). Add a `pinact run --check` pre-commit hook so future PRs stay pinned. Re-pin when the action releases a new version — Dependabot can do this automatically with `version-update-strategy: inc
GitHub Actions `uses:` reference is not pinned to a 40-character commit SHA. Tags (`@v4`) and branches (`@main`) are mutable — a compromised maintainer or a tag rewrite can substitute malicious code into your CI pipeline silently. Pin to a SHA: `uses: actions/checkout@8e5e7e5ab8b370d6c329ec480221332ada57f0ab`. For readability, include the version as a trailing comment: `# v4.1.1`. Tools like `pinact` / `ratchet` automate this. Allowed unpinned forms (excluded by the rule): - Local actions `.
Evidence
| 19 | uses: actions/checkout@v6.0.1 |
| 20 | |
| 21 | - name: Run Trivy (Go dependencies) |
| 22 | uses: aquasecurity/trivy-action@0.34.0 |
| 23 | with: |
| 24 | scan-type: fs |
| 25 | scan-ref: . |
Remediation
Pin every `uses:` to a 40-character commit SHA. Trailing comment with the version helps reviewers: `uses: actions/checkout@8e5e7e5ab8b370d6c329ec480221332ada57f0ab # v4.1.1` Automate the migration with `pinact` (https://github.com/suzuki-shunsuke/pinact) or `ratchet` (https://github.com/sethvargo/ratchet). Add a `pinact run --check` pre-commit hook so future PRs stay pinned. Re-pin when the action releases a new version — Dependabot can do this automatically with `version-update-strategy: inc
GitHub Actions `uses:` reference is not pinned to a 40-character commit SHA. Tags (`@v4`) and branches (`@main`) are mutable — a compromised maintainer or a tag rewrite can substitute malicious code into your CI pipeline silently. Pin to a SHA: `uses: actions/checkout@8e5e7e5ab8b370d6c329ec480221332ada57f0ab`. For readability, include the version as a trailing comment: `# v4.1.1`. Tools like `pinact` / `ratchet` automate this. Allowed unpinned forms (excluded by the rule): - Local actions `.
Evidence
| 15 | steps: |
| 16 | - name: Checkout |
| 17 | uses: actions/checkout@v6 |
| 18 | |
| 19 | - name: Set up Go |
| 20 | uses: actions/setup-go@v6 |
Remediation
Pin every `uses:` to a 40-character commit SHA. Trailing comment with the version helps reviewers: `uses: actions/checkout@8e5e7e5ab8b370d6c329ec480221332ada57f0ab # v4.1.1` Automate the migration with `pinact` (https://github.com/suzuki-shunsuke/pinact) or `ratchet` (https://github.com/sethvargo/ratchet). Add a `pinact run --check` pre-commit hook so future PRs stay pinned. Re-pin when the action releases a new version — Dependabot can do this automatically with `version-update-strategy: inc
GitHub Actions `uses:` reference is not pinned to a 40-character commit SHA. Tags (`@v4`) and branches (`@main`) are mutable — a compromised maintainer or a tag rewrite can substitute malicious code into your CI pipeline silently. Pin to a SHA: `uses: actions/checkout@8e5e7e5ab8b370d6c329ec480221332ada57f0ab`. For readability, include the version as a trailing comment: `# v4.1.1`. Tools like `pinact` / `ratchet` automate this. Allowed unpinned forms (excluded by the rule): - Local actions `.
Evidence
| 23 | runs-on: macos-latest |
| 24 | steps: |
| 25 | - name: Checkout |
| 26 | uses: actions/checkout@v6 |
| 27 | |
| 28 | - uses: actions/setup-go@v6 |
| 29 | with: |
Remediation
Pin every `uses:` to a 40-character commit SHA. Trailing comment with the version helps reviewers: `uses: actions/checkout@8e5e7e5ab8b370d6c329ec480221332ada57f0ab # v4.1.1` Automate the migration with `pinact` (https://github.com/suzuki-shunsuke/pinact) or `ratchet` (https://github.com/sethvargo/ratchet). Add a `pinact run --check` pre-commit hook so future PRs stay pinned. Re-pin when the action releases a new version — Dependabot can do this automatically with `version-update-strategy: inc
GitHub Actions `uses:` reference is not pinned to a 40-character commit SHA. Tags (`@v4`) and branches (`@main`) are mutable — a compromised maintainer or a tag rewrite can substitute malicious code into your CI pipeline silently. Pin to a SHA: `uses: actions/checkout@8e5e7e5ab8b370d6c329ec480221332ada57f0ab`. For readability, include the version as a trailing comment: `# v4.1.1`. Tools like `pinact` / `ratchet` automate this. Allowed unpinned forms (excluded by the rule): - Local actions `.
Evidence
| 23 | platforms: all |
| 24 | |
| 25 | - name: Set up Docker Buildx |
| 26 | uses: docker/setup-buildx-action@v3 |
| 27 | id: buildx |
| 28 | |
| 29 | - name: Login to GitHub Container Registry |
Remediation
Pin every `uses:` to a 40-character commit SHA. Trailing comment with the version helps reviewers: `uses: actions/checkout@8e5e7e5ab8b370d6c329ec480221332ada57f0ab # v4.1.1` Automate the migration with `pinact` (https://github.com/suzuki-shunsuke/pinact) or `ratchet` (https://github.com/sethvargo/ratchet). Add a `pinact run --check` pre-commit hook so future PRs stay pinned. Re-pin when the action releases a new version — Dependabot can do this automatically with `version-update-strategy: inc