CVE-2026-90769: Open Notebook before 1.11.0 Server-Side Request Forgery via link-source

Q: Who can exploit this issue?

An authenticated Open Notebook user can exploit it. The vulnerable endpoint is POST /api/sources, and no user interaction is required.

Q: What systems or data could be exposed?

The application server can be induced to make HTTP requests to arbitrary URLs, including cloud metadata endpoints, internal network services, and services bound only to localhost. Exposure depends on what the Open Notebook server can reach from its network position.

Q: Are default deployments affected?

The provided information identifies affected versions as Open Notebook before 1.11.0, but does not state whether any particular default configuration enables or prevents exploitation.

Q: What can be done if upgrading is not immediately possible?

The provided data does not specify an official workaround. Reducing access to authenticated users and restricting the application server's outbound network access would limit access to internal, localhost, and cloud metadata services, but implementation details are not provided.

Published Sep 13, 2026

Updated

Open Notebook before 1.11.0 fails to validate the URL parameter in POST /api/sources endpoint, allowing authenticated users to perform server-side requests to internal services. Attackers can supply arbitrary URLs to read cloud metadata, internal network services, and localhost-bound services through the application server's direct HTTP requests.

Affected Software

1 affected component

Open Notebook<1.11.0

Event History

Sep 13, 2026

CVE Published

via MITRE·10:45 AM

Data Sourced

via MITRE·10:45 AM

DescriptionSeverityWeakness

Frequently Asked Questions

Who can exploit this issue?

An authenticated Open Notebook user can exploit it. The vulnerable endpoint is POST /api/sources, and no user interaction is required.

What systems or data could be exposed?

The application server can be induced to make HTTP requests to arbitrary URLs, including cloud metadata endpoints, internal network services, and services bound only to localhost. Exposure depends on what the Open Notebook server can reach from its network position.

Are default deployments affected?

The provided information identifies affected versions as Open Notebook before 1.11.0, but does not state whether any particular default configuration enables or prevents exploitation.

What can be done if upgrading is not immediately possible?

The provided data does not specify an official workaround. Reducing access to authenticated users and restricting the application server's outbound network access would limit access to internal, localhost, and cloud metadata services, but implementation details are not provided.

CVE-2026-90769: Open Notebook before 1.11.0 Server-Side Request Forgery via link-source

Affected Software

Event History

Frequently Asked Questions

Who can exploit this issue?

What systems or data could be exposed?

Are default deployments affected?

What can be done if upgrading is not immediately possible?

Company

Resources

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Frequently Asked Questions

Who can exploit this issue?

What systems or data could be exposed?

Are default deployments affected?

What can be done if upgrading is not immediately possible?