CVE-2026-108852: Deep Chat through 2.5.1 XSS via Markdown Link Validation Bypass
Deep Chat through 2.5.1 contains a cross-site scripting vulnerability that allows attackers to inject javascript: links because RemarkableConfig.createNew disables Remarkable link validation. Attackers can place crafted Markdown links in AI responses, addMessage content, or loaded history to execute script in the embedding page when victims click them.
Affected Software
Event History
Frequently Asked Questions
Where can attacker-controlled content enter the vulnerable Markdown renderer?
Crafted Markdown links can be introduced through AI responses, addMessage content, or loaded chat history. The script executes in the embedding page when a victim clicks the rendered link.
What must an attacker and victim do for exploitation to succeed?
An attacker must place a crafted javascript: Markdown link into one of the affected content paths. A victim must then click that link, so exploitation requires user interaction.
Are deployments affected by a configuration change?
The issue is caused by RemarkableConfig.createNew disabling Remarkable link validation. The provided information does not identify a separate opt-in configuration requirement beyond use of the affected Markdown rendering behavior.
What versions are identified as affected?
Deep Chat through version 2.5.1 is identified as affected. No fixed version is provided.