CVE-2026-7528: IBM Langflow OSS DoS Vulnerability

CVE-2026-7528 Overview

CVE-2026-7528 is a denial of service vulnerability affecting IBM Langflow OSS versions 1.0.0 through 1.9.0. The flaw stems from uncontrolled resource consumption [CWE-400] and can be triggered by an authenticated attacker over the network. Successful exploitation allows an adversary to exhaust system resources and render the Langflow service unavailable to legitimate users.

Langflow is an open-source framework used to build agentic and retrieval-augmented generation (RAG) workflows. Service disruption affects downstream applications that depend on these flows for production inference and orchestration.

Critical Impact

An authenticated attacker can remotely exhaust resources on an IBM Langflow OSS instance, causing service-wide denial of service across hosted AI workflows.

Affected Products

• IBM Langflow OSS 1.0.0
• IBM Langflow OSS versions 1.0.0 through 1.9.0
• Deployments of IBM Langflow OSS prior to the fixed release

Discovery Timeline

• 2026-05-27 - CVE CVE-2026-7528 published to NVD
• 2026-05-27 - Last updated in NVD database

Technical Details for CVE-2026-7528

Vulnerability Analysis

The vulnerability is classified under [CWE-400] Uncontrolled Resource Consumption. IBM Langflow OSS fails to enforce adequate limits on resources consumed during request processing. An authenticated user with low privileges can submit input that causes the service to allocate excessive CPU, memory, or other backend resources.

Because Langflow orchestrates language model pipelines and component graphs, request handling involves expensive operations such as graph evaluation, model invocation, and data transformation. Without bounded execution, these operations can be weaponized into a sustained denial of service against the host process.

The impact is limited to availability, with high availability impact but no integrity loss. The confidentiality impact is low, suggesting limited side-channel exposure during resource exhaustion.

Root Cause

The root cause is the absence of enforced resource limits and input validation on operations exposed through the Langflow API. The application does not constrain the size, depth, or computational cost of user-supplied workflow data before processing it.

Attack Vector

The attack is delivered over the network and requires low privileges with no user interaction. An authenticated attacker submits crafted requests to the Langflow service that trigger resource-intensive paths. Repeated or amplified requests degrade or halt service availability for all tenants on the affected instance.

No verified proof-of-concept code has been published. Refer to the IBM Support Page for vendor-supplied technical detail.

Detection Methods for CVE-2026-7528

Indicators of Compromise

• Sustained spikes in CPU or memory utilization on hosts running IBM Langflow OSS without a corresponding increase in legitimate workflow throughput.
• Repeated authenticated API requests from a single principal that correlate with resource exhaustion events or service restarts.
• Langflow process crashes, out-of-memory kills, or container restarts logged by the orchestration layer.

Detection Strategies

• Baseline normal request rates, payload sizes, and execution durations for the Langflow API, then alert on statistically significant deviations.
• Inspect application logs for long-running flow executions or repeated timeouts tied to the same authenticated session.
• Correlate authentication events with downstream resource utilization to attribute exhaustion patterns to specific accounts or API tokens.

Monitoring Recommendations

• Enable verbose request logging on the Langflow service and forward logs to a centralized analytics platform for retention and query.
• Monitor container and host telemetry, including CPU throttling, memory pressure, and OOM events on Langflow workloads.
• Track authentication failure and success ratios per source to identify credential abuse preceding resource exhaustion.

How to Mitigate CVE-2026-7528

Immediate Actions Required

• Identify all instances of IBM Langflow OSS running versions 1.0.0 through 1.9.0 in development, staging, and production environments.
• Apply the vendor-provided fix referenced in the IBM Support Page as soon as practical.
• Restrict network exposure of the Langflow API to trusted networks and authenticated service principals only.
• Rotate and audit API credentials used to authenticate against Langflow to limit the blast radius of abused accounts.

Patch Information

IBM has published remediation guidance on the IBM Support Page. Upgrade IBM Langflow OSS to a fixed release as specified in the vendor advisory. Validate the upgrade in a non-production environment before rolling out broadly.

Workarounds

• Place IBM Langflow OSS behind a reverse proxy or API gateway that enforces request rate limits, payload size caps, and execution timeouts.
• Deploy Langflow under resource quotas using container limits or systemd cgroups to bound CPU and memory per process.
• Require strong authentication and scope-limited API tokens so that compromised low-privilege accounts cannot reach the vulnerable endpoints at scale.

# Example: enforce per-container resource limits in Kubernetes
resources:
  limits:
    cpu: "2"
    memory: "4Gi"
  requests:
    cpu: "500m"
    memory: "1Gi"