Cyber Resilience

CVE-2026-33017

RCE in Langflow ≤ 1.8.2

CISA KEVActive ExploitationEUVD ExploitedPublic PoCRCEAccess Control
Published
20 March 2026
Modified
21 May 2026
KEV Added
25 March 2026
Patch / advisory
CVSS Score v4 9.3
Click a component to see what it means
Raw vectorCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:L/SI:L/SA:L/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
EPSS Score 0.96 99.9th percentile
Risk Priority 75 floored blend · peak EPSS

Summary

CVE-2026-33017 is a critical-severity Code Injection (CWE-94) vulnerability in Langflow Langflow. Its CVSS base score is 9.3 (Critical).

Operationally, exploitation aligns with the MITRE ATT&CK technique JavaScript (T1059.007); ranked in the top 0.1% of CVEs by exploit likelihood; CISA has added it to the Known Exploited Vulnerabilities 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 AC-14 (Permitted Actions Without Identification or Authentication) and IA-2 (Identification and Authentication (Organizational Users)) — 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.

Langflow, a framework for building and deploying AI-powered agents and workflows, contains an unauthenticated remote code execution vulnerability in versions prior to 1.9.0. The flaw resides in the POST /api/v1/build_public_tmp/{flow_id}/flow endpoint, which is intentionally reachable without authentication for public flows. When an optional data parameter is supplied, the endpoint substitutes attacker-controlled flow definitions—containing arbitrary Python code in node definitions—for the stored database record and passes the input directly to an unsandboxed exec() call.

An unauthenticated attacker can therefore submit a malicious flow payload to achieve arbitrary code execution on the server, obtaining full control over the host process, data, and any connected resources. The issue stems from missing authentication combined with insufficient validation of externally supplied flow data, distinct from the earlier CVE-2025-3248 fix that added authentication to the /api/v1/validate/code endpoint.

Public advisories and the project repository indicate that the vulnerability is resolved in Langflow 1.9.0; the referenced commit and release notes document the corrective changes that prevent the endpoint from accepting and executing attacker-supplied code.

The affected component is central to AI workflow tooling, increasing the potential blast radius in environments that expose Langflow instances. Exploitation probability rose from lower values to a peak of 0.4365 on 2026-05-12 before receding to the current 0.2465, indicating post-disclosure attacker interest.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

Langflow is a tool for building and deploying AI-powered agents and workflows. In versions prior to 1.9.0, the POST /api/v1/build_public_tmp/{flow_id}/flow endpoint allows building public flows without requiring authentication. When the optional data parameter is supplied, the endpoint uses attacker-controlled flow…

more

data (containing arbitrary Python code in node definitions) instead of the stored flow data from the database. This code is passed to exec() with zero sandboxing, resulting in unauthenticated remote code execution. This is distinct from CVE-2025-3248, which fixed /api/v1/validate/code by adding authentication. The build_public_tmp endpoint is designed to be unauthenticated (for public flows) but incorrectly accepts attacker-supplied flow data containing arbitrary executable code. This issue has been fixed in version 1.9.0.

CWE(s)
KEV Date Added
25 March 2026

AI Security AnalysisAI

AI Category
LLM Application Platforms
Risk Domain
LLM/Generative AI Risks
OWASP Top 10 for LLMs 2025
None mapped
Classification Reason
Matched keywords: ai, langflow

Related Threats

MITRE ATT&CK Enterprise Techniques

T1059.007 JavaScript Execution
Adversaries may abuse various implementations of JavaScript for execution.
T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
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.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2025-3248Same product: Langflow Langflowboth on KEV
CVE-2026-9198Same product: Langflow Langflowboth on KEV
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-2026-27966Same product: Langflow Langflow
CVE-2026-12822Same product: Langflow Langflow

Affected Assets

langflow
langflow
≤ 1.8.2

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)
  • 6 hardening rules · 3 OS baselines
Validate
Prove the fix (OWASP ASVS)
  • V6.2.3
  • V6.4.4
  • V10.4.16
  • V12.1.3

Mitigating Controls (NIST 800-53 r5) AI

Directly mandates unique identification and authentication of users before access to functions requiring identity.

Extends the same authentication requirement to non-organizational users accessing critical functionality.

Requires authentication of services before they can invoke or expose critical functions.

Explicitly identifies and limits actions permitted without authentication, preventing critical functions from being exposed.

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.

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.AA-03 full match
prevents

Directly requires authentication of users/services/hardware, which eliminates missing authentication for critical functions.

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.AA-01 partial match
prevents

Managing identities and credentials is a prerequisite for authentication but does not itself enforce it on critical functions.

PR.AA-05 partial match
prevents

Defining and enforcing authorizations assumes prior authentication and therefore only partially mitigates the absence of authentication.

PR.IR-01 partial match
prevents

Protecting networks from unauthorized access can be undermined by missing authentication but does not address the root authentication gap.

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

The control explicitly calls for authentication before any critical function is reached, eliminating the possibility of bypassing authentication for high-value operations.

finds

Security testing in development can detect eval injection vulnerabilities before deployment.

prevents

Mandating authentication requirements for critical functions at the requirements-gathering stage ensures that essential operations are not left unprotected by missing login or verification mechanisms.

mitigates

Mandating authentication for network services and critical functions stops attackers from invoking sensitive operations without credentials, closing gaps where authentication is absent for important capabilities.

prevents

Secure development life cycle mandates input validation and safe coding practices that directly prevent eval injection.

prevents

Application security requirements include rules against dynamic code execution of untrusted input.

Hardening callouts derived

Configuration rules from DISA STIG baselines that bear on weaknesses of the type cited by this CVE. Each rule is shown with the relationship its mapping actually records, against the CWE it was authored against. Derived via CVE→CWE over `controls_xwalks` (authoritative rows only; rows rated `none` are excluded).

Oracle Linux 8 (2 rules)
  • V-248585 OL 8 must require reauthentication when using the "sudo" command. prevents CWE-306
  • V-248827 OL 8 must not have the rsh-server package installed. prevents CWE-306
RHEL 7 (2 rules)
  • V-204442 The Red Hat Enterprise Linux operating system must not have the rsh-server package installed. prevents CWE-306
  • V-237635 The Red Hat Enterprise Linux operating system must require re-authentication when using the "sudo" command. prevents CWE-306
RHEL 8 (2 rules)
  • V-230492 RHEL 8 must not have the rsh-server package installed. prevents CWE-306
  • V-237643 RHEL 8 must require re-authentication when using the "sudo" command. prevents CWE-306

References