CVE-2026-19295: Langflow RCE Vulnerability

CVE-2026-19295 Overview

IBM Langflow OSS versions 1.0.0 through 1.11.1 contain a command injection vulnerability that allows an authenticated attacker to execute arbitrary operating system commands on the server. The flaw resides in the flow-building logic, which processes a crafted type field value when a wrapper flow references a saved malicious flow. Successful exploitation grants command execution under the server process identity and bypasses the LANGFLOW_ALLOW_CUSTOM_COMPONENTS=false policy control. This transforms a low-privileged authenticated flow user into an operator with full OS-level command execution [CWE-95].

Critical Impact
Authenticated attackers can escalate privileges to arbitrary OS command execution, bypassing the custom component restriction and compromising the Langflow server host.

Affected Products

IBM Langflow OSS 1.0.0
IBM Langflow OSS versions 1.0.0 through 1.11.1
Langflow deployments with LANGFLOW_ALLOW_CUSTOM_COMPONENTS=false

Discovery Timeline

2026-08-28 - CVE-2026-19295 published to NVD
2026-09-01 - Last updated in NVD database

Technical Details for CVE-2026-19295

Vulnerability Analysis

Langflow is an open-source framework for building agentic AI and retrieval workflows. The vulnerability exists in how the server processes the type field of a saved flow during a build operation. An authenticated user can save a flow that embeds attacker-controlled content into the type field, then trigger a build of a wrapper flow that references it. During the build, the crafted value is evaluated by the server, which results in arbitrary OS command execution under the server process identity.

The policy control LANGFLOW_ALLOW_CUSTOM_COMPONENTS=false is intended to prevent users from introducing executable custom components. This vulnerability bypasses that boundary entirely, defeating a documented hardening posture.

Root Cause

The root cause is improper neutralization of directives in dynamically evaluated code [CWE-95]. The type field is not restricted to a safe set of identifiers, and the wrapper-flow build path evaluates it in a context that reaches OS command execution. Input validation and allow-listing on the type field are insufficient to constrain values to expected component types.

Attack Vector

Exploitation requires network access to the Langflow API and valid authenticated credentials for a flow user. The attacker performs two steps: save a flow containing a malicious type value, then request a build of a wrapper flow that references the saved flow. The build operation executes the injected command in the server process. Because the flaw affects a scoped operation with impact beyond the vulnerable component, a compromised Langflow instance can be used to pivot into adjacent systems, exfiltrate secrets from the environment, or backdoor stored flows.

No verified public exploit code is available. See the IBM Support advisory for vendor-supplied technical details.

Detection Methods for CVE-2026-19295

Indicators of Compromise

Unexpected child processes spawned by the Langflow server process (for example, sh, bash, python, curl, wget)
Saved flows containing non-standard values in the type field that do not match known component identifiers
Outbound network connections from the Langflow host to unknown infrastructure shortly after flow build events
New or modified files in Langflow working directories written by the server process identity

Detection Strategies

Audit Langflow API logs for POST requests that save flows followed by build requests referencing those flows from the same authenticated principal
Correlate flow-build events with process creation telemetry on the host to identify command execution originating from the Langflow runtime
Review authenticated user activity for accounts creating flows with unusual type payloads or embedded shell metacharacters

Monitoring Recommendations

Enable process ancestry logging on Langflow hosts and alert when the server process spawns shells or interpreters
Forward Langflow application logs and host EDR telemetry into a central data lake for cross-source correlation
Monitor egress from Langflow servers and baseline expected destinations to surface anomalous outbound activity

How to Mitigate CVE-2026-19295

Immediate Actions Required

Upgrade Langflow to a version later than 1.11.1 that contains the vendor fix as referenced in the IBM Support advisory
Restrict network access to the Langflow API to trusted administrators and internal networks only
Rotate credentials, API keys, and secrets stored in or accessible from Langflow, assuming potential exposure on affected hosts
Audit saved flows for suspicious type field values and remove untrusted content

Patch Information

Refer to the IBM Support advisory for Langflow OSS for the fixed version and upgrade guidance. Do not rely on LANGFLOW_ALLOW_CUSTOM_COMPONENTS=false as a mitigation, since this vulnerability bypasses that control.

Workarounds

Limit Langflow authentication to trusted operators and disable self-registration if enabled
Run the Langflow server as an unprivileged user in an isolated container with read-only filesystem and no outbound internet access where possible
Apply network segmentation so the Langflow host cannot reach sensitive internal services
Enforce egress filtering to allow-listed destinations to reduce post-exploitation impact

bash

# Configuration example: run Langflow with reduced privileges and no egress
docker run --rm \
  --user 10001:10001 \
  --read-only \
  --cap-drop=ALL \
  --network=langflow-internal \
  --env LANGFLOW_ALLOW_CUSTOM_COMPONENTS=false \
  langflowai/langflow:latest