What’s Vulnerable › Vulnerabilities

CVE-2026-108852: Deep Chat through 2.5.1 XSS via Markdown Link Validation Bypass

• Severity: medium (CVSS 4.7 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.2% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-10-11 · updated 2026-10-16
• Weakness: CWE-79

Description

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 products

• OvidijusParsiunas Deep Chat: from 1.4.7 through 2.5.1

References

• https://github.com/OvidijusParsiunas/deep-chat
• https://github.com/OvidijusParsiunas/deep-chat/blob/2.5.1/component/src/views/chat/messages/remarkable/remarkableConfig.ts#L74-L78
• https://hackmd.io/@1ExmmukzRMWN7B4gQ4W-4Q/ovidijusparsiunas-deep-chat-markdown-scheme-validation
• https://www.vulncheck.com/advisories/deep-chat-through-2.5.1-xss-via-markdown-link-validation-bypass

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