LearningCircuit local-deep-research up to 1.5.x HTML Document ssrf_validator.py PDFService._markdown_to_html HTML injection

Summaryinfo

A vulnerability, which was classified as problematic, has been found in LearningCircuit local-deep-research up to 1.5.x. This affects the function PDFService._markdown_to_html of the file ssrf_validator.py of the component HTML Document Handler. Performing a manipulation results in HTML injection. This vulnerability is known as CVE-2026-43979. Remote exploitation of the attack is possible. No exploit is available. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability classified as problematic has been found in LearningCircuit local-deep-research up to 1.5.x. This affects the function PDFService._markdown_to_html of the file ssrf_validator.py of the component HTML Document Handler. The manipulation with an unknown input leads to a html injection vulnerability. CWE is classifying the issue as CWE-79. The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users. This is going to have an impact on integrity. The summary by CVE is:

Local Deep Research is an AI-powered research assistant for deep, iterative research. Prior to 1.6.0, PDFService._markdown_to_html() constructs an HTML document by interpolating user-controlled values — specifically title (sourced from research.title or research.query) and metadata key-value pairs — directly into an f-string without any HTML escaping. An authenticated attacker can craft a research query containing HTML special characters to inject arbitrary HTML tags into the document processed by WeasyPrint during PDF export. This injection can be chained to trigger a Server-Side Request Forgery (SSRF), bypassing the application's existing SSRF defenses in ssrf_validator.py. This vulnerability is fixed in 1.6.0.

The advisory is shared at github.com. This vulnerability is uniquely identified as CVE-2026-43979 since 05/04/2026. The exploitability is told to be easy. It is possible to initiate the attack remotely. It demands that the victim is doing some kind of user interaction. Technical details are known, but no exploit is available. MITRE ATT&CK project uses the attack technique T1059.007 for this issue.

Upgrading to version 1.6.0 eliminates this vulnerability. Applying a patch is able to eliminate this problem. The bugfix is ready for download at github.com. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-32978). If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Productinfo

Vendor

• LearningCircuit

Name

• local-deep-research

Version

• 1.0
• 1.1
• 1.2
• 1.3
• 1.4
• 1.5

Website

• Product: https://github.com/LearningCircuit/local-deep-research/

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If you want to get the best quality for vulnerability data then you always have to consider VulDB.

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