How severe is CVE-2026-27966?

CVE-2026-27966 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2026-27966 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 34% (98th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-27966?

CVE-2026-27966 affects Langflow. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-27966?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

Does CVE-2026-27966 have an EU (EUVD) identifier?

Yes. CVE-2026-27966 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-8819.

When was CVE-2026-27966 published?

CVE-2026-27966 was published on 2026-02-26 and last updated on 2026-06-17.

CVE-2026-27966

CVE-2026-27966 is a critical-severity vulnerability in Langflow with a CVSS 3.x base score of 9.8. Its EPSS exploit-prediction score of 34% places it in the 98th percentile, indicating an elevated likelihood of exploitation. The underlying weakness is classified as CWE-94.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
EPSS exploit prediction: 34% (98th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-8819
Weakness: CWE-94
Affected product: Langflow
Published: 2026-02-26
Last modified: 2026-06-17

Description

Langflow is a tool for building and deploying AI-powered agents and workflows. Prior to version 1.8.0, the CSV Agent node in Langflow hardcodes `allow_dangerous_code=True`, which automatically exposes LangChain’s Python REPL tool (`python_repl_ast`). As a result, an attacker can execute arbitrary Python and OS commands on the server via prompt injection, leading to full Remote Code Execution (RCE). Version 1.8.0 fixes the issue.

Frequently asked questions

What is CVE-2026-27966?: Langflow is a tool for building and deploying AI-powered agents and workflows. Prior to version 1.8.0, the CSV Agent node in Langflow hardcodes `allow_dangerous_code=True`, which automatically exposes LangChain’s Python REPL tool (`python_repl_ast`). As a result, an attacker can execute arbitrary Python and OS commands on the server via prompt injection, leading to full Remote Code Execution (RCE). Version 1.8.0 fixes the issue.
How severe is CVE-2026-27966?: CVE-2026-27966 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2026-27966 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 34% (98th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-27966?: CVE-2026-27966 affects Langflow. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-27966?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
Does CVE-2026-27966 have an EU (EUVD) identifier?: Yes. CVE-2026-27966 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-8819.
When was CVE-2026-27966 published?: CVE-2026-27966 was published on 2026-02-26 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:langflow:langflow:*:*:*:*:*:*:*:*

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