CVE-2026-7524: IBM Langflow OSS RCE Vulnerability

CVE-2026-7524 Overview

CVE-2026-7524 is a path traversal vulnerability in IBM Langflow OSS versions 1.0.0 through 1.9.1. The flaw stems from improper validation of symbolic links during archive extraction [CWE-22]. Attackers can craft malicious archives that, when extracted by Langflow, write files outside the intended directory. This behavior enables remote code execution on affected servers without authentication or user interaction.

Critical Impact

Unauthenticated attackers can achieve remote code execution by uploading crafted archives, leading to full compromise of IBM Langflow OSS deployments.

Affected Products

• IBM Langflow OSS 1.0.0
• IBM Langflow OSS versions 1.0.1 through 1.9.0
• IBM Langflow OSS 1.9.1

Discovery Timeline

• 2026-05-27 - CVE CVE-2026-7524 published to NVD
• 2026-05-27 - Last updated in NVD database

Technical Details for CVE-2026-7524

Vulnerability Analysis

IBM Langflow OSS processes archive files as part of its component and flow import functionality. The extraction routine does not validate symbolic link targets contained inside the archive. An attacker can include a symlink entry pointing to an arbitrary path on the host, followed by a regular file entry that writes through that symlink. The extractor follows the symlink and writes attacker-controlled content to any location accessible by the Langflow process.

This primitive allows writing into Python site-packages, systemd unit files, cron directories, or application startup scripts. Each of these targets converts a file write into code execution. Because Langflow exposes archive ingestion over the network, exploitation requires no authentication and no user interaction.

The issue is classified under CWE-22: Improper Limitation of a Pathname to a Restricted Directory. It is a variant commonly referred to as a Zip Slip or TarSlip vulnerability when symlinks are involved.

Root Cause

The extraction logic trusts archive metadata and does not canonicalize the resolved path against the extraction root. Symbolic link entries are written to disk before subsequent entries are processed, allowing later writes to traverse the symlink target outside the sandbox directory.

Attack Vector

An attacker sends a crafted tar or zip archive to a Langflow endpoint that accepts component or flow imports. The archive contains a symlink entry such as link -> /etc followed by a payload entry link/cron.d/payload. Upon extraction, the payload is written into /etc/cron.d/, where it executes with the privileges of the Langflow service.

The vulnerability is described in the IBM Support advisory. No verified public proof-of-concept code is currently available.

Detection Methods for CVE-2026-7524

Indicators of Compromise

• Unexpected files appearing under system directories such as /etc/cron.d/, /etc/systemd/system/, or Python site-packages after Langflow archive uploads.
• Langflow process spawning child processes outside its normal execution profile, such as sh, bash, or python invocations tied to newly written files.
• Archive uploads to Langflow import endpoints containing symbolic link entries with absolute or traversal targets.

Detection Strategies

• Inspect archives received by Langflow for symlink entries whose targets resolve outside the intended extraction directory.
• Monitor file integrity on directories writable by the Langflow service account, alerting on writes from the Langflow process to paths outside its working directory.
• Correlate HTTP requests to Langflow upload endpoints with subsequent filesystem modifications and process creation events.

Monitoring Recommendations

• Enable verbose logging on Langflow ingestion endpoints and forward logs to a centralized SIEM for retention and correlation.
• Audit outbound network connections initiated by the Langflow process, which may indicate post-exploitation command-and-control activity.
• Track version inventory of Langflow OSS deployments and alert when instances running 1.0.0 through 1.9.1 are detected.

How to Mitigate CVE-2026-7524

Immediate Actions Required

• Upgrade IBM Langflow OSS to a fixed version as listed in the IBM Support advisory.
• Restrict network access to Langflow management and import endpoints to trusted administrators only.
• Run the Langflow process as a non-privileged user with no write access to system directories.

Patch Information

IBM has published remediation guidance on the IBM Support page for CVE-2026-7524. Administrators should consult the advisory for the specific fixed version and apply it across all affected deployments.

Workarounds

• Disable archive import functionality in Langflow until patches are applied.
• Place Langflow inside a container or chroot with read-only bind mounts for sensitive host paths, limiting the impact of arbitrary file writes.
• Add a reverse proxy rule that blocks uploads of tar and zip archives to Langflow endpoints until remediation is complete.

# Configuration example: restrict Langflow service privileges via systemd
[Service]
User=langflow
Group=langflow
ProtectSystem=strict
ProtectHome=true
ReadWritePaths=/var/lib/langflow
NoNewPrivileges=true