CVE-2026-69253

CVE-2026-69253 is a high-severity vulnerability in Flowiseai Flowise with a CVSS 3.x base score of 8.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-95.

Key facts

Description

Flowise is a drag-and-drop user interface for building customized large language model (LLM) flows. Prior to version 3.1.3, several custom-tool components — AgentAsTool, ChatflowTool, and ExecuteFlow — ran code in the in-process  vm2  sandbox. To build that code, they inserted a user-controlled  baseURL  value straight into the JavaScript source, for example  const url = "${baseURL}/..."; . The only check on  baseURL  was  isValidURL , but a valid-looking URL can still contain characters that break out of a code string. An authenticated user could craft a  baseURL  that passed this check, closed the surrounding string, and injected their own JavaScript into the sandboxed script (code injection, CWE-94). The  vm2  sandbox runs in the same Node.js process as Flowise and exposes risky dependencies. As a result, the injected code could escape the sandbox and run arbitrary code on the Flowise server as the Flowise process user. Exploitation only requires an authenticated session. The issue is fixed in version 3.1.3, which passes the URL to the sandbox as data instead of inserting it into code and adds stricter URL validation.

Frequently asked questions

What is CVE-2026-69253?
Flowise is a drag-and-drop user interface for building customized large language model (LLM) flows. Prior to version 3.1.3, several custom-tool components — AgentAsTool, ChatflowTool, and ExecuteFlow — ran code in the in-process  vm2  sandbox. To build that code, they inserted a user-controlled  baseURL  value straight into the JavaScript source, for example  const url = "${baseURL}/..."; . The only check on  baseURL  was  isValidURL , but a valid-looking URL can still contain characters that break out of a code string. An authenticated user could craft a  baseURL  that passed this check, closed the surrounding string, and injected their own JavaScript into the sandboxed script (code injection, CWE-94). The  vm2  sandbox runs in the same Node.js process as Flowise and exposes risky dependencies. As a result, the injected code could escape the sandbox and run arbitrary code on the Flowise server as the Flowise process user. Exploitation only requires an authenticated session. The issue is fixed in version 3.1.3, which passes the URL to the sandbox as data instead of inserting it into code and adds stricter URL validation.
How severe is CVE-2026-69253?
CVE-2026-69253 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2026-69253 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (50th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-69253?
CVE-2026-69253 affects Flowiseai Flowise. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-69253?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2026-69253 published?
CVE-2026-69253 was published on 2026-08-04 and last updated on 2026-09-14.

References

Affected products (1)

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Threat intelligence

Threat-intel indicators referencing this CVE: