CVE-2026-8661

MEDIUMPre-NVD 4.84.8—
EchelonGraph scoreMEDIUM 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
4.8EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 4.8Exploit: None knownExposed: 0

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

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.

CVSS v3
4.8
EG Score
4.8(medium)
EG Risk
22(Track)
EG Risk 22/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity48% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
16%
KEV
Not listed

Published

June 26, 2026

Last Modified

July 24, 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 5× in last 7d / 54× 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.

Showing the most recent 100 of 163 total refreshes for this CVE.

  1. 2026-09-11 14:53 UTCEPSS rescore
  2. 2026-09-11 09:38 UTCEPSS rescore
  3. 2026-09-08 22:01 UTCEPSS rescore
  4. 2026-09-06 13:48 UTCEPSS rescore
  5. 2026-09-05 15:31 UTCEPSS rescore
  6. 2026-09-04 05:07 UTCEPSS rescore
  7. 2026-09-02 14:12 UTCEPSS rescore
  8. 2026-09-01 13:54 UTCEPSS rescore
  9. 2026-09-01 04:40 UTCEPSS rescore
  10. 2026-08-30 19:26 UTCEG score recompute
  11. 2026-08-30 19:26 UTCGHSA enrichment
  12. 2026-08-30 19:18 UTCEPSS rescore
  13. 2026-08-30 01:22 UTCEPSS rescore
  14. 2026-08-28 21:42 UTCEPSS rescore
  15. 2026-08-27 23:14 UTCEG score recompute
  16. 2026-08-27 23:14 UTCGHSA enrichment
  17. 2026-08-27 14:25 UTCEPSS rescore
  18. 2026-08-26 14:47 UTCEPSS rescore
  19. 2026-08-25 13:49 UTCEPSS rescore
  20. 2026-08-24 14:18 UTCEPSS rescore
  21. 2026-08-24 13:07 UTCEG score recompute
  22. 2026-08-24 13:07 UTCGHSA enrichment
  23. 2026-08-23 10:58 UTCEG score recompute
  24. 2026-08-23 10:58 UTCGHSA enrichment
  25. 2026-08-23 00:19 UTCEPSS rescore
Show 75 more
  1. 2026-08-22 09:51 UTCEG score recompute
  2. 2026-08-22 09:51 UTCGHSA enrichment
  3. 2026-08-21 23:49 UTCEPSS rescore
  4. 2026-08-21 08:07 UTCEG score recompute
  5. 2026-08-21 08:07 UTCGHSA enrichment
  6. 2026-08-20 22:56 UTCEPSS rescore
  7. 2026-08-20 06:59 UTCEG score recompute
  8. 2026-08-20 06:59 UTCGHSA enrichment
  9. 2026-08-19 17:04 UTCEPSS rescore
  10. 2026-08-19 01:07 UTCEG score recompute
  11. 2026-08-19 01:06 UTCGHSA enrichment
  12. 2026-08-18 13:49 UTCEPSS rescore
  13. 2026-08-18 13:49 UTCEPSS rescore
  14. 2026-08-17 13:47 UTCEPSS rescore
  15. 2026-08-17 06:11 UTCEG score recompute
  16. 2026-08-17 06:11 UTCGHSA enrichment
  17. 2026-08-16 14:56 UTCEPSS rescore
  18. 2026-08-16 14:56 UTCEPSS rescore
  19. 2026-08-16 04:21 UTCEG score recompute
  20. 2026-08-16 04:21 UTCGHSA enrichment
  21. 2026-08-16 02:15 UTCEPSS rescore
  22. 2026-08-15 03:14 UTCEG score recompute
  23. 2026-08-15 03:14 UTCGHSA enrichment
  24. 2026-08-15 01:31 UTCEPSS rescore
  25. 2026-08-14 02:06 UTCEG score recompute
  26. 2026-08-14 02:06 UTCGHSA enrichment
  27. 2026-08-13 22:00 UTCEPSS rescore
  28. 2026-08-13 00:59 UTCEG score recompute
  29. 2026-08-13 00:59 UTCGHSA enrichment
  30. 2026-08-12 13:51 UTCEPSS rescore
  31. 2026-08-11 23:51 UTCEG score recompute
  32. 2026-08-11 23:51 UTCGHSA enrichment
  33. 2026-08-11 13:43 UTCEPSS rescore
  34. 2026-08-11 00:00 UTCEPSS rescore
  35. 2026-08-10 22:44 UTCGHSA enrichment
  36. 2026-08-09 21:36 UTCEG score recompute
  37. 2026-08-09 21:36 UTCGHSA enrichment
  38. 2026-08-09 13:47 UTCEPSS rescore
  39. 2026-08-08 20:29 UTCEG score recompute
  40. 2026-08-08 20:29 UTCGHSA enrichment
  41. 2026-08-08 16:37 UTCEPSS rescore
  42. 2026-08-07 19:21 UTCEG score recompute
  43. 2026-08-07 19:21 UTCGHSA enrichment
  44. 2026-08-07 16:30 UTCEPSS rescore
  45. 2026-08-06 18:14 UTCEG score recompute
  46. 2026-08-06 18:14 UTCGHSA enrichment
  47. 2026-08-06 13:47 UTCEPSS rescore
  48. 2026-08-05 19:17 UTCEPSS rescore
  49. 2026-08-05 19:17 UTCEPSS rescore
  50. 2026-08-05 17:07 UTCGHSA enrichment
  51. 2026-08-04 15:59 UTCEG score recompute
  52. 2026-08-04 15:59 UTCGHSA enrichment
  53. 2026-08-04 15:10 UTCEPSS rescore
  54. 2026-08-04 10:39 UTCEPSS rescore
  55. 2026-08-03 14:52 UTCEG score recompute
  56. 2026-08-03 14:52 UTCGHSA enrichment
  57. 2026-08-03 10:36 UTCEPSS rescore
  58. 2026-08-02 13:44 UTCEG score recompute
  59. 2026-08-02 13:44 UTCGHSA enrichment
  60. 2026-08-02 02:27 UTCEPSS rescore
  61. 2026-08-01 12:37 UTCEG score recompute
  62. 2026-08-01 12:36 UTCGHSA enrichment
  63. 2026-08-01 04:16 UTCEPSS rescore
  64. 2026-07-31 11:25 UTCEG score recompute
  65. 2026-07-31 11:24 UTCGHSA enrichment
  66. 2026-07-30 16:28 UTCEPSS rescore
  67. 2026-07-30 09:59 UTCEG score recompute
  68. 2026-07-30 09:59 UTCGHSA enrichment
  69. 2026-07-30 01:30 UTCEPSS rescore
  70. 2026-07-29 08:51 UTCEG score recompute
  71. 2026-07-29 08:51 UTCGHSA enrichment
  72. 2026-07-28 15:37 UTCEPSS rescore
  73. 2026-07-28 07:38 UTCEG score recompute
  74. 2026-07-28 07:38 UTCGHSA enrichment
  75. 2026-07-27 14:14 UTCEPSS rescore

Frequently asked(5)

What is CVE-2026-8661?
CVE-2026-8661 is a medium vulnerability published on June 26, 2026. Server-Side Request Forgery in the markdowntopdf 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…
When was CVE-2026-8661 disclosed?
CVE-2026-8661 was first published in the National Vulnerability Database on June 26, 2026, with the most recent update on July 24, 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 0% probability of exploitation in the next 30 days, which ranks it in the top 84.3% of all scored CVEs.
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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