Is CVE-2026-8661 in the CISA KEV catalog?

No. CVE-2026-8661 is not currently on the CISA Known Exploited Vulnerabilities list.

What is the CVSS severity of CVE-2026-8661?

CVE-2026-8661 has a CVSS v3 base score of 4.8 (MEDIUM).

What is the EPSS score for CVE-2026-8661?

CVE-2026-8661 has an EPSS score of 0.25% (17th percentile), estimating the probability of exploitation in the next 30 days.

How do I fix or mitigate CVE-2026-8661?

No published fix for CVE-2026-8661 has been found yet. Check the linked vendor advisories for guidance as it becomes available.

CVE & CISA-KEV Catalog

CVE-2026-8661

MEDIUM

4.8

CVSS v3

NVD

Description

Server-Side Cross-Site Scripting and Server-Side Request Forgery vulnerability in the markdown_to_pdf action of Rapid7 InsightConnect Markdown Plugin version 3.1.4 and earlier on Linux allows remote attackers to execute JavaScript server-side and make arbitrary outbound HTTP requests via crafted content embedded in Markdown input. The PDF rendering engine does not restrict script execution or outbound network access.

CWE-79Cross-Site Scripting (XSS)CWE-918Server-Side Request Forgery (SSRF)

How to fix

No published remediation has been found for this vulnerability's affected products yet.

Mitigation guidance may be in the linked vendor advisories in the References section below.

CVSS v3 Vector

Exploitability

Attack VectorNetwork

Attack ComplexityHigh

Privileges RequiredNone

User InteractionNone

ScopeUnchanged

Impact

ConfidentialityLow

IntegrityLow

AvailabilityNone

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N

Exploit Intelligence

0.25%probability of exploitation in 30 days

17thpercentile

Low risk: more likely to be exploited than 17% of all known CVEs.

References

Other references2

Embed a live status badge for CVE-2026-8661

Markdown

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HTML

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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-06-26.