CVE-2026-8478: IBM Langflow OSS RCE Vulnerability

CVE-2026-8478 Overview

CVE-2026-8478 is a code injection vulnerability affecting IBM Langflow OSS versions 1.0.0 through 1.10.3. The flaw stems from improper control of user-supplied input code, allowing a remote authenticated attacker to inject and execute arbitrary code on the underlying system. Langflow OSS is an open-source framework used to build workflows for large language model (LLM) applications, making it a common component in AI development pipelines. Successful exploitation compromises the confidentiality, integrity, and availability of the host running Langflow. The weakness is categorized under CWE-94: Improper Control of Generation of Code.

Critical Impact
Remote authenticated attackers can execute arbitrary code on systems running IBM Langflow OSS 1.0.0 through 1.10.3, leading to full host compromise.

Affected Products

IBM Langflow OSS 1.0.0 through 1.10.3
Deployments embedding Langflow as an LLM workflow orchestrator
Container and cloud-hosted instances exposing the Langflow API

Discovery Timeline

2026-08-05 - CVE-2026-8478 published to NVD
2026-08-06 - Last updated in NVD database

Technical Details for CVE-2026-8478

Vulnerability Analysis

CVE-2026-8478 arises because Langflow accepts user-provided code as part of its workflow definition and passes that input to an execution context without sufficient validation or sandboxing. Langflow permits authors to define custom components and expressions used during flow execution. When the code path responsible for materializing these components does not restrict Python constructs or dangerous built-ins, an attacker can supply payloads that execute in the server process. The result is arbitrary code execution under the privileges of the Langflow service account.

Because Langflow is frequently deployed as a shared service for data scientists and LLM engineers, the impacted process often has access to API keys, model endpoints, and internal network resources. An attacker who compromises the host can pivot to model theft, prompt data exfiltration, or lateral movement into connected AI infrastructure.

Root Cause

The root cause is improper control of user input code [CWE-94]. Langflow evaluates workflow-supplied code without enforcing a strict allow-list of operations, so unsafe modules and functions remain reachable during flow parsing or execution.

Attack Vector

The vulnerability is exploitable over the network. An authenticated user with permission to create or modify flows submits a crafted flow containing malicious code. When the flow is validated or executed, the payload runs on the server. No user interaction beyond the attacker's own request is required.

No public proof-of-concept exploit is listed in the enriched data. Refer to the IBM Support Page for technical detail on the affected code paths.

Detection Methods for CVE-2026-8478

Indicators of Compromise

Unexpected child processes spawned by the Langflow service, especially shells (sh, bash) or interpreters (python, curl, wget).
Outbound network connections from the Langflow host to unfamiliar IP addresses or paste sites shortly after flow creation or execution.
New or modified flow definitions containing Python constructs such as __import__, eval, exec, subprocess, or os.system.
Anomalous file writes under Langflow working directories, including scripts, cron entries, or SSH keys.

Detection Strategies

Inspect Langflow application logs for flow create, update, and run events containing suspicious code fragments.
Correlate authenticated API activity with process execution telemetry on the Langflow host to identify code-injection chains.
Alert on Langflow processes performing actions inconsistent with LLM workflow orchestration, such as invoking package managers or network scanners.

Monitoring Recommendations

Forward Langflow API access logs and host process telemetry to a central analytics platform for correlation.
Monitor egress traffic from Langflow hosts and baseline expected model and API destinations.
Track user accounts with flow-authoring privileges and review additions or permission changes.

How to Mitigate CVE-2026-8478

Immediate Actions Required

Upgrade IBM Langflow OSS to a version above 1.10.3 as directed on the IBM Support Page.
Restrict network access to the Langflow interface so only trusted users and networks can reach it.
Audit existing flows for unexpected Python code, exec/eval usage, or references to system commands.
Rotate any credentials, API keys, or model tokens accessible to the Langflow service account.

Patch Information

IBM has published remediation guidance for CVE-2026-8478 on the IBM Support Page. Apply the fixed release identified in that advisory to all Langflow OSS deployments in the 1.0.0 through 1.10.3 range.

Workarounds

Limit flow-authoring privileges to a small set of trusted operators and disable public or anonymous access.
Run Langflow inside a hardened container with a read-only filesystem, dropped Linux capabilities, and no outbound internet access by default.
Enforce egress filtering and network segmentation so a compromised Langflow host cannot reach sensitive internal services.
Enable authentication and multi-factor verification on any reverse proxy fronting the Langflow API.

bash

# Example: restrict Langflow container privileges and network exposure
docker run --rm \
  --read-only \
  --cap-drop=ALL \
  --security-opt=no-new-privileges \
  --user 10001:10001 \
  --network langflow-internal \
  -p 127.0.0.1:7860:7860 \
  langflowai/langflow:<patched-version>