CVE-2026-10140 Overview
CVE-2026-10140 affects IBM Langflow OSS versions 1.0.0 through 1.10.0 in the voice mode component. The vulnerability stems from improper shared-state handling that permits reuse of API clients across tenant boundaries [CWE-639]. An authenticated attacker can manipulate cache state to force requests from other users to execute with incorrect upstream API credentials. This results in cross-tenant billing misattribution and broken accountability tracking within multi-tenant Langflow deployments.
Critical Impact
Authenticated attackers can cause other tenants' voice-mode requests to be processed with attacker-influenced API credentials, breaking billing integrity and tenant isolation.
Affected Products
- IBM Langflow OSS 1.0.0
- IBM Langflow OSS versions 1.0.0 through 1.10.0
- Langflow voice mode component
Discovery Timeline
- 2026-06-30 - CVE-2026-10140 published to NVD
- 2026-07-02 - Last updated in NVD database
Technical Details for CVE-2026-10140
Vulnerability Analysis
The vulnerability resides in the voice mode subsystem of IBM Langflow OSS. Langflow maintains cached API client instances to reduce initialization overhead for upstream large language model providers. The caching layer fails to bind cached clients to the tenant context that created them. Requests from separate authenticated tenants can retrieve the same cached client. This shared-state condition maps to Authorization Bypass Through User-Controlled Key [CWE-639].
When a tenant issues a voice-mode request, Langflow selects an API client from the shared cache. The upstream provider then processes the request using credentials that belong to a different tenant. Usage metering, quota enforcement, and audit logs attribute the operation to the credential owner rather than the requester.
Root Cause
The root cause is missing tenant scoping in the API client cache key. Cache lookups use provider or model identifiers without incorporating tenant identity. Authenticated users can influence cache population and retrieval to select clients bound to other tenants' credentials.
Attack Vector
Exploitation requires network access and valid authentication to the Langflow instance. The attacker interacts with voice-mode endpoints to prime the shared cache. Concurrent requests from victim tenants then retrieve the poisoned client entries. No user interaction from victims is required, and the scope change indicates impact extends beyond the vulnerable component to billing and identity systems.
No verified proof-of-concept code is publicly available. Refer to the IBM Support Documentation for vendor-supplied technical detail.
Detection Methods for CVE-2026-10140
Indicators of Compromise
- Upstream LLM provider billing records showing usage spikes that do not correlate with tenant activity logs in Langflow.
- Audit entries where the API key owner and the authenticated Langflow user identity diverge for the same request.
- Unexpected voice-mode request volume from a single authenticated principal shortly before cross-tenant billing anomalies.
Detection Strategies
- Correlate Langflow application logs with upstream provider API access logs, matching request timestamps against credential identifiers.
- Alert on any voice-mode request where the resolved API client credential does not match the tenant of the authenticated session.
- Monitor cache-hit patterns in the voice-mode component for entries that service multiple tenant identifiers.
Monitoring Recommendations
- Enable verbose logging on voice-mode endpoints, capturing tenant ID, cache key, and resolved credential identifier per request.
- Forward Langflow and upstream provider logs to a centralized analytics platform for cross-source correlation.
- Establish per-tenant baselines for voice-mode request volume and billing to detect misattribution.
How to Mitigate CVE-2026-10140
Immediate Actions Required
- Upgrade IBM Langflow OSS to a fixed release beyond version 1.10.0 as directed in the IBM Support Documentation.
- Restrict voice-mode access to trusted tenants until patching is complete.
- Rotate upstream provider API keys used by Langflow to invalidate any cached credentials that may have leaked across tenants.
Patch Information
IBM has published remediation guidance in the IBM Support Documentation. Administrators should apply the fixed release identified by the vendor and validate that the API client cache is tenant-scoped after upgrade.
Workarounds
- Disable the voice mode feature in Langflow configuration where operationally feasible.
- Deploy separate Langflow instances per tenant to eliminate shared cache state between tenant boundaries.
- Enforce network-level segmentation so that a compromised authenticated user cannot reach voice-mode endpoints serving other tenants.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
