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Open NotebookApplication · Lfnovo

CVE-2026-33587

CRITICAL · 10.0 CVSS v3.1 Published 2026-05-07
Fix available
A fix is available. Upgrade to 1.8.4 or later.
See remediation →
100/100
Remediation priority · Urgent
Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
Lack of user input sanitisation in Open Notebook v1.8.3 allows the application user to execute Python code (and subsequently OS commands) on the docker container via Server-Side Template Injection (SSTI) for user-created transformations.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

Open Notebook v1.8.3 contains an SSTI vulnerability in its user-created transformation functionality. User-supplied input is not sanitized before being embedded into template contexts, allowing attackers to inject template syntax that gets interpreted by the server-side template engine, enabling arbitrary Python code execution and subsequent OS command execution within the Docker container.

MitigationImplement strict input validation and use sandboxed template rendering (e.g., Jinja2's SandboxedEnvironment) or a safer alternative to disable arbitrary code execution in user transformation inputs.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Open NotebookApplication
Affected:< 1.8.4

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Changed
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify Open Notebook version
    Check the installed version of Open Notebook by reviewing the application metadata, package files, or the application's 'about' or 'version' endpoint. Common locations include the main application directory, a VERSION file, or the Docker image labels.
    Affected if The installed version is less than 1.8.4 (e.g., 1.8.3, 1.8.2, or earlier)
  2. Locate transformation functionality
    Identify where user-created transformations are defined in the Open Notebook application. Look for transformation configuration files, templates, or code modules related to the transformation feature mentioned in the documentation or application structure.
    Affected if The transformation feature exists and user-created transformations are present in the environment
  3. Inspect transformation input handling
    Review the transformation code or configuration to determine how user input is processed. Examine template files that accept user-supplied data and check whether the input is passed directly into a template context without sanitization.
    Affected if User-provided input is embedded into template contexts without filtering or escaping of template syntax
  4. Examine transformation templates for SSTI indicators
    Review existing user-created transformations for suspicious patterns such as {{, {%, {{config, or Python code constructs (e.g., __import__, os.system, subprocess). Compare against known malicious payload patterns used in template injection attacks.
    Affected if Template syntax injection is possible and the application interprets user input as template code

A user is affected if running Open Notebook version below 1.8.4 and the user-created transformation functionality is active with unsanitized input flowing into template rendering.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 1.8.4 or later
Fixed in 1.8.4
Interim mitigation

Implement strict input validation and use sandboxed template rendering (e.g., Jinja2's SandboxedEnvironment) or a safer alternative to disable arbitrary code execution in user transformation inputs.

Recommended fix High confidence

Upgrade to Open Notebook version 1.8.4 or later

  1. Backup any existing notebooks, configurations, and data from the current Open Notebook installation
  2. Stop the Open Notebook service/container
  3. Upgrade Open Notebook to version 1.8.4 or later
  4. Verify that the upgrade completed successfully
  5. Restart the Open Notebook service
  6. Test that the application functions normally and that user-created transformations no longer allow arbitrary code execution
Caveat Review release notes for 1.8.4 to check for any breaking changes in configuration or functionality

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Open Notebook Scoped from the published advisory
  • Consultation4.0 h
  • Implementation16.0 h
  • Testing8.0 h
  • Review / QA4.0 h
32.0 hours of engineering $5,600
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $8,960.

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-33587 in production — separate from our analysis above.

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data