CVE-2026-8661Network attack vector

SSRF via unsanitized Markdown resource loading

Published Jun 26, 2026 · Updated Jun 26, 2026

SSRF in Rapid7 InsightConnect Markdown Plugin before 4.0.2 allows remote attackers to make arbitrary outbound HTTP requests. The markdown_to_pdf action passes resource-loading HTML generated from crafted Markdown to its PDF renderer without restricting img src, CSS url(), or @import targets. No authentication or user interaction is required; destinations reachable from the Linux orchestrator can receive attacker-controlled requests.

CVSS severity4.8
Medium
EPSS probability0.24%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

SSRF in Rapid7 InsightConnect Markdown Plugin before 4.0.2 allows remote attackers to make arbitrary outbound HTTP requests. The markdown_to_pdf action passes resource-loading HTML generated from crafted Markdown to its PDF renderer without restricting img src, CSS url(), or @import targets. No authentication or user interaction is required; destinations reachable from the Linux orchestrator can receive attacker-controlled requests.

The record

CVE
CVE-2026-8661
Published
Jun 26, 2026
Updated
Jun 26, 2026
Vendor
Rapid7
Product
Markdown
Classifications
CWE-79, CWE-918, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 26, 2026CVE publishedPublication date reported by the CVE source.
  2. Jun 26, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <4.0.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Rapid7 · Markdownversion=0 <4.0.0

Published CVSS scores

4.8Rapid7, Inc.CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
CWE-918Server-Side Request Forgery (SSRF)
T1190Exploit Public-Facing Application

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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