CVE-2026-8661

MEDIUMPre-NVD 4.84.8—
EchelonGraph scoreHIGH confidence

Score 4.8 from GitHub Security Advisory published 2026-06-26. a secondary CVSS source baseline 4.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 3 sources updated this week
4.8
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS: 0%CVSS: 4.8Exploit: NoneExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

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.

CVSS v3
4.8
EG Score
4.8(high)
EPSS
16.8%
KEV
Not listed

Published

June 26, 2026

Last Modified

June 26, 2026

Advisory Details (2)

Auto-updated Jun 26, 2026
Upstream fix merged — awaiting tagged release. Sources: github_pr.
github_pr

Markdown SDK Bump and Spec Cleanup

Fix merged in rapid7/insightconnect-plugins PR #3721 on 2026-02-12 — awaiting tagged release

https://github.com/rapid7/insightconnect-plugins/pull/3721
generic

insightconnect-plugins/plugins/markdown/help.md at master · rapid7/insightconnect-plugins · GitHub

https://github.com/rapid7/insightconnect-plugins/blob/master/plugins/markdown/help.md

Vendor Advisories for CVE-2026-8661(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Weakness Classification(2)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 25× in last 7d / 37× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-07-06 16:27 UTCEPSS rescore
  2. 2026-07-06 16:27 UTCEPSS rescore
  3. 2026-07-06 15:39 UTCEG score recompute
  4. 2026-07-06 15:39 UTCGHSA enrichment
  5. 2026-07-06 02:23 UTCEPSS rescore
  6. 2026-07-06 02:23 UTCEPSS rescore
  7. 2026-07-05 14:27 UTCEG score recompute
  8. 2026-07-05 14:27 UTCGHSA enrichment
  9. 2026-07-05 02:31 UTCEPSS rescore
  10. 2026-07-05 02:30 UTCEPSS rescore
  11. 2026-07-04 13:19 UTCEG score recompute
  12. 2026-07-04 13:19 UTCGHSA enrichment
  13. 2026-07-04 06:31 UTCEPSS rescore
  14. 2026-07-04 06:31 UTCEPSS rescore
  15. 2026-07-03 12:10 UTCEG score recompute
  16. 2026-07-03 12:10 UTCGHSA enrichment
  17. 2026-07-02 10:58 UTCEG score recompute
  18. 2026-07-02 10:58 UTCGHSA enrichment
  19. 2026-07-02 10:56 UTCGHSA enrichment
  20. 2026-07-01 15:07 UTCEPSS rescore
  21. 2026-07-01 09:29 UTCEG score recompute
  22. 2026-07-01 09:29 UTCGHSA enrichment
  23. 2026-06-30 23:22 UTCEPSS rescore
  24. 2026-06-30 08:21 UTCEG score recompute
  25. 2026-06-30 08:21 UTCGHSA enrichment
Show 12 more
  1. 2026-06-29 14:06 UTCEPSS rescore
  2. 2026-06-29 07:13 UTCEG score recompute
  3. 2026-06-29 07:13 UTCGHSA enrichment
  4. 2026-06-28 14:07 UTCEPSS rescore
  5. 2026-06-28 06:05 UTCEG score recompute
  6. 2026-06-28 06:05 UTCGHSA enrichment
  7. 2026-06-28 04:56 UTCEPSS rescore
  8. 2026-06-27 04:55 UTCEG score recompute
  9. 2026-06-27 04:55 UTCGHSA enrichment
  10. 2026-06-27 03:08 UTCEPSS rescore
  11. 2026-06-26 03:46 UTCEG score recompute
  12. 2026-06-26 03:46 UTCGHSA enrichment

Frequently asked(5)

What is CVE-2026-8661?
CVE-2026-8661 is a medium vulnerability published on June 26, 2026. Server-Side Cross-Site Scripting and Server-Side Request Forgery vulnerability in the markdowntopdf 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…
When was CVE-2026-8661 disclosed?
CVE-2026-8661 was first published in the National Vulnerability Database on June 26, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-8661 actively exploited?
CVE-2026-8661 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 16.8% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-8661?
CVE-2026-8661 has a CVSS v3 base score of 4.8 (NVD).
How do I remediate CVE-2026-8661?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-8661, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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