CVE-2026-90769

Open Notebook before 1.11.0 Server-Side Request Forgery via link-source

Published Sep 13, 2026 CVSS 4.0 · 8.3 High EPSS < 1% KEV · Not listed

Description

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.

Analysis

Technical impact

The Open Notebook application, for releases before 1.11.0, does not validate the URL supplied to the POST /api/sources endpoint. This flaw, classified as CWE-918, allows any authenticated user to instruct the server to perform an HTTP request to an arbitrary address. By choosing internal or cloud‑metadata URLs, an attacker can read sensitive data, probe internal services, or same host as the application, thereby exposing a range of internal resources.

Affected Systems

The vulnerability affects installations of lfnovo open‑notebook that are built with a version less than 1.11.0. Any deployment of that software using an older release, regardless of operating system or hosting environment, is susceptible.

Risk and Exploitability

The CVSS score of 8.3 indicates a high severity impact. The EPSS score is available but very low, at <1%, indicating a low probability of exploitation. The absence of URL validation provides a straightforward path for authenticated users to reach internal services. The vulnerability is not currently listed in the CISA KEV catalog, and there are no known public exploits, though its nature makes it attractive for attackers once credentials are obtained.

Affected Products

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions

lfnovo

open-notebook

unaffected

Version	Status	Constraints
`0`	affected	< 1.11.0

No data.

Vendor Product Versions

Lfnovo

Open-notebook

Version	Status	Scheme	Platform
`[0,1.11.0)`	affected	semver	—

Remediation

No solution or workaround provided in the CVE record.

OpenCVE Recommended Actions

Upgrade to Open Notebook version 1.11.0 or newer to correct the URL validation flaw.
If an upgrade is delayed, limit the POST /api/sources endpoint to a whitelist of trusted URLs or block the endpoint for unauthenticated traffic.
Review and reduce user permissions in the application to remove any unnecessary elevated privileges that could aid exploitation.

Generated by OpenCVE AI on September 15, 2026 at 16:59 UTC.

Tracking

Advisories

No advisories available

Metrics

Attack Vector Network

Attack Complexity Low

Privileges Required Low

Attack Requirements None

User Interaction None

Vulnerable System Confidentiality Impact High

Vulnerable System Integrity Impact None

Vulnerable System Availability Impact None

Subsequent System Confidentiality Impact High

Subsequent System Integrity Impact None

Subsequent System Availability Impact None

Attack Vector Network

Attack Complexity Low

Privileges Required Low

Scope Changed

Confidentiality Impact High

Integrity Impact None

Availability Impact None

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

Exploit prediction score: < 1% (0.415% probability within 30 days)

Exploitation poc

Automatable no

Technical Impact partial

References

Link	Providers
https://github.com/lfnovo/open-notebook
https://github.com/lfnovo/open-notebook/blob/8889087e317177d7b6e286342ab34e0c9c01d43e/api/routers/sources.py
https://github.com/lfnovo/open-notebook/commit/9045ea50196927eac7de647bb5b7009349236fb4
https://github.com/lfnovo/open-notebook/issues/1284
https://www.vulncheck.com/advisories/open-notebook-before-1.11.0-server-side-request-forgery-via-link-source

History

Sep 14, 2026 9:00 PM Scoring metrics updated View changes

Type	Values Removed	Values Added
Metrics		ssvc `{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}`

Sep 13, 2026 11:00 AM Description updated. Title updated. First appearance in the feed. Weaknesses updated. Affected versions updated. Affected vendors updated. Added references. Scoring metrics updated View changes

Type	Values Removed	Values Added
Description		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.
Title		Open Notebook before 1.11.0 Server-Side Request Forgery via link-source
First Time appeared		Lfnovo Lfnovo open-notebook
Weaknesses		CWE-918
CPEs		cpe:2.3:a:lfnovo:open-notebook::::::::
Vendors & Products		Lfnovo Lfnovo open-notebook
References		https://github.com/lfnovo/open-notebook https://github.com/lfnovo/open-notebook/blob/8889087e317177d7b6e286342ab34e0c9c01d43e/api/routers/sources.py https://github.com/lfnovo/open-notebook/commit/9045ea50196927eac7de647bb5b7009349236fb4 https://github.com/lfnovo/open-notebook/issues/1284 https://www.vulncheck.com/advisories/open-notebook-before-1.11.0-server-side-request-forgery-via-link-source
Metrics		cvssV3_1 `{'score': 7.7, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N'}` cvssV4_0 `{'score': 8.3, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:H/SI:N/SA:N'}`