CVE-2026-56274

CRITICALPre-NVD 9.99.9—
EchelonGraph scoreMEDIUM confidence

Score 9.9 from GitHub Security Advisory (severity: HIGH) published 2026-06-23. a secondary CVSS source baseline 9.9; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 3 sources updated this weekWeaponized
9.9EG
EchelonGraph verdictPatch this weekExploitation is likely or a public exploit exists.
  • Public exploit code is available (Metasploit, ssvc poc, public exploit)
CISA-KEV: Not listedEPSS PROB: 8%CVSS: 9.9Exploit: Metasploit · ssvc poc · public exploitExposed: 0

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

Flowise before 3.1.2 contains multiple OS command injection vulnerabilities in the Custom MCP Server feature due to incomplete command-flag validation and a regex bypass in local file access restrictions. An attacker with a Flowise account of any role, or API access with view/update permissions for chatflows, can configure a malicious MCP server to bypass the validateCommandFlags blocklist (for example, 'docker build' is not blocked, and 'npx --yes' is not blocked while only '-y' is) and the validateArgsForLocalFileAccess checks, resulting in execution of arbitrary commands on the Flowise host.

CVSS v3
9.9
EG Score
9.9(medium)
EG Risk
71(Track*)
EG Risk 71/100SSVC: 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
Severity99% × 45%
Exploitation65% × 40%
Automatability0% × 15%
Action: Watch closely — could escalate to Attend.
EPSS PROB
8%
EPSS %ILE
94%
KEV
Not listed

Published

June 23, 2026

Last Modified

June 25, 2026

Advisory Details (2)

Auto-updated Aug 23, 2026
🔬 Proof of concept available. Patch available. Sources: github.
github Patch Available🟡 PoC Available

Flowise MCP Security Bypass Enables RCE · Advisory · FlowiseAI/Flowise · GitHub

https://github.com/FlowiseAI/Flowise/security/advisories/GHSA-m99r-2hxc-cp3q
generic

Flowise - Remote Code Execution via MCP Security Bypass in validateCommandFlags and validateArgsForLocalFileAccess | Advisories | VulnCheck

https://www.vulncheck.com/advisories/flowise-remote-code-execution-via-mcp-security-bypass-in-validatecommandflags-and-validateargsforlocalfileaccess

Vendor Advisories for CVE-2026-56274(1)

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

Affected Packages

(2 across 1 ecosystem)
npm(2)
PackageVulnerable rangeFixed inDependents
flowise—3.1.2—
flowise-components—3.1.2—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 38× in last 7d / 187× 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 368 total refreshes for this CVE.

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

Publicly available exploits

(1 reference)

Working exploit code is in the public domain (1 Metasploit module). Defenders should treat patch urgency accordingly — public PoCs typically lead to mass-exploitation within 24-72 hours.

  • Metasploitexploit/multi/http/flowise_mcp_rce✓ verified
    First seen Jun 23, 2026

    Flowise MCP Server Remote Code Execution

    Open source ↗

Frequently asked(5)

What is CVE-2026-56274?
CVE-2026-56274 is a critical vulnerability published on June 23, 2026. Flowise before 3.1.2 contains multiple OS command injection vulnerabilities in the Custom MCP Server feature due to incomplete command-flag validation and a regex bypass in local file access restrictions. An attacker with a Flowise account of any role, or API access with view/update permissions for…
When was CVE-2026-56274 disclosed?
CVE-2026-56274 was first published in the National Vulnerability Database on June 23, 2026, with the most recent update on June 25, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-56274 actively exploited?
CVE-2026-56274 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 8% probability of exploitation in the next 30 days, which ranks it in the top 6.0% of all scored CVEs.
What is the CVSS score of CVE-2026-56274?
CVE-2026-56274 has a CVSS v3 base score of 9.9 (NVD).
How do I remediate CVE-2026-56274?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-56274, 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

See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-56274

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