What’s Vulnerable › Vulnerabilities

CVE-2026-8661: Server-Side Cross-Site Scripting and SSRF in Rapid7 InsightConnect Markdown to PDF Plugin

• Severity: medium (CVSS 4.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.4% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-06-26 · updated 2026-10-25
• Weakness: CWE-79

Description

Server-Side Request Forgery in the markdown_to_pdf action of Rapid7 InsightConnect Markdown Plugin on Linux in versions prior to 4.0.2 allows remote attackers to make arbitrary outbound HTTP requests via unsanitized resource-loading HTML elements (img/src, CSS url(), @import) embedded in Markdown input. The initial fix in 4.0.0 disabled JavaScript but did not neutralize resource-loading vectors. Resolved in 4.0.2 by sanitizing HTML with an allowlist of tags, attributes, and URL schemes.

Affected products

• Rapid7 InsightConnect Markdown Plugin: before 4.0.2 — fixed in 4.0.2

How to fix

Upgrade to a fixed version: Rapid7 InsightConnect Markdown Plugin 4.0.2. Check the vendor advisory for mitigations.

References

• https://github.com/rapid7/insightconnect-plugins/blob/master/plugins/markdown/help.md
• https://github.com/rapid7/insightconnect-plugins/pull/3721
• https://github.com/rapid7/insightconnect-plugins/pull/4010

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