Is CVE-2026-56274 in the CISA KEV catalog?

No. CVE-2026-56274 is not currently on the CISA Known Exploited Vulnerabilities list.

What is the CVSS severity of CVE-2026-56274?

CVE-2026-56274 has a CVSS v3 base score of 9.9 (CRITICAL).

What is the EPSS score for CVE-2026-56274?

CVE-2026-56274 has an EPSS score of 1.66% (74th percentile), estimating the probability of exploitation in the next 30 days.

CVE & CISA-KEV Catalog

CVE-2026-56274

CRITICALEPSS 74th pctl

9.9

CVSS v3

NVD

Description

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.

CWE-78OS Command Injection

CVSS v3 Vector

Exploitability

Attack VectorNetwork

Attack ComplexityLow

Privileges RequiredLow

User InteractionNone

ScopeChanged

Impact

ConfidentialityHigh

IntegrityHigh

AvailabilityHigh

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

Exploit Intelligence

1.66%probability of exploitation in 30 days

74thpercentile

Elevated risk: more likely to be exploited than 74% of all known CVEs.

References

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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 2026-06-24.