Cyber Resilience

CVE-2026-27966

RCE in Langflow ≤ 1.8.0

Public PoCRCE
Published
26 February 2026
Modified
28 February 2026
Patch / advisory
CVSS Score v3.1 9.8
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.34 98th percentile
Risk Priority 89 floored blend · peak EPSS

Summary

CVE-2026-27966 is a critical-severity Code Injection (CWE-94) vulnerability in Langflow Langflow. Its CVSS base score is 9.8 (Critical).

Operationally, exploitation aligns with the MITRE ATT&CK technique Command and Scripting Interpreter (T1059); ranked in the top 2% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

This vulnerability is AI-related — categorised as LLM Application Platforms; in the LLM/Generative AI Risks risk domain.

The strongest mitigations our analysis identified map to SA-11 (Developer Testing and Evaluation) and SI-10 (Information Input Validation) — see the control section below for these in your framework.

Deeper analysis AI-assisted summary

Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.

CVE-2026-27966 is a critical remote code execution vulnerability in Langflow, an open-source tool for building and deploying AI-powered agents and workflows. In versions prior to 1.8.0, the CSV Agent node hardcodes the `allow_dangerous_code=True` parameter, which automatically exposes LangChain's Python REPL tool (`python_repl_ast`). This flaw, classified under CWE-94 (Code Injection) with a CVSS v3.1 base score of 9.8 (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H), enables attackers to execute arbitrary Python code and operating system commands on the affected server through prompt injection attacks.

The vulnerability can be exploited by any unauthenticated attacker with network access to the Langflow instance, requiring no privileges, user interaction, or special complexity. Successful exploitation grants full remote code execution (RCE), allowing attackers to run malicious Python scripts or OS commands, potentially leading to complete server compromise, data theft, persistence, or lateral movement within the environment.

The Langflow security advisory (GHSA-3645-fxcv-hqr4) and the fixing commit (d8c6480daa17b2f2af0b5470cdf5c3d28dc9e508) confirm that upgrading to version 1.8.0 resolves the issue by addressing the hardcoded dangerous code allowance in the CSV Agent node.

This vulnerability highlights risks in AI/ML workflow tools like Langflow, where prompt injection can bypass safeguards in agentic systems relying on LangChain components. No public evidence of real-world exploitation has been reported as of the CVE publication on 2026-02-26.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

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…

more

Python and OS commands on the server via prompt injection, leading to full Remote Code Execution (RCE). Version 1.8.0 fixes the issue.

CWE(s)

AI Security AnalysisAI

AI Category
LLM Application Platforms
Risk Domain
LLM/Generative AI Risks
OWASP Top 10 for LLMs 2025
None mapped
AI-specific weaknesses CR
  • CWE-1426 — Hardcoded dangerous tool flag lets LLM/agent output reach code-execution sink; prompt injection is delivery vector.
Mapped by Cyber Resilience · not in NVD. Poisoning and extraction cases are routed to MITRE ATLAS instead of a synthetic CWE.
Classification Reason
Matched keywords: ai, langchain, langflow, prompt injection

Related Threats

MITRE ATT&CK Enterprise Techniques

T1059 Command and Scripting Interpreter Execution
Adversaries may abuse command and script interpreters to execute commands, scripts, or binaries.
T1059.001 PowerShell Execution
Adversaries may abuse PowerShell commands and scripts for execution.
T1059.002 AppleScript Execution
Adversaries may abuse AppleScript for execution.
T1059.004 Unix Shell Execution
Adversaries may abuse Unix shell commands and scripts for execution.
T1059.005 Visual Basic Execution
Adversaries may abuse Visual Basic (VB) for execution.
T1059.006 Python Execution
Adversaries may abuse Python commands and scripts for execution.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2026-0771Same product: Langflow Langflow
CVE-2024-48061Same product: Langflow Langflow
CVE-2026-33873Same product: Langflow Langflow
CVE-2026-9196Same product: Langflow Langflow
CVE-2026-0768Same product: Langflow Langflow
CVE-2026-48519Same product: Langflow Langflow
CVE-2026-8478Same product: Langflow Langflow
CVE-2026-17633Same product: Langflow Langflow
CVE-2026-8182Same product: Langflow Langflow
CVE-2026-9198Same product: Langflow Langflow

Affected Assets

langflow
langflow
≤ 1.8.0

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)

Validate
Prove the fix (OWASP ASVS)
  • V1.3.1

Mitigating Controls (NIST 800-53 r5) AI

Developer testing and evaluation finds code paths that accept and execute externally influenced strings.

Input validation directly stops untrusted data from being used to construct executable code without neutralization.

Least privilege limits the damage an injected code fragment can perform once executed.

Requiring documented secure development standards and tools enforces use of safe code-generation APIs and escaping.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match
prevents

PR.PS-06's SDLC practices directly target injection flaws via secure coding and testing (mostly), yet as a single broad outcome it leaves many code-generation specifics unaddressed (partial).

PR.DS-10 none match
prevents

PR.DS-10 protects runtime data confidentiality/integrity but has no bearing on neutralizing externally influenced input during code generation, so neither direction shows any preventive effect.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

prevents

Banning unapproved code samples and unauthenticated web services, combined with secure-coding standards and SAST, prevents the dynamic generation or inclusion of attacker-supplied code.

none

Controls that restrict unauthorized or malicious code from being introduced via external networks or removable media limit opportunities for an attacker to inject and execute arbitrary code.

References