CVE-2026-8470: IBM Langflow OSS Encryption Vulnerability

CVE-2026-8470 Overview

CVE-2026-8470 affects IBM Langflow OSS versions 1.0.0 through 1.10.3. The application derives Fernet encryption keys from user-supplied secrets shorter than 32 characters using Python's random module, a non-cryptographic pseudo-random number generator. The Mersenne Twister PRNG produces deterministic output for identical seeds. Attackers who know or can guess a short user secret can reproduce the resulting encryption key and decrypt stored API keys and authentication tokens. The weakness is classified under [CWE-327] Use of a Broken or Risky Cryptographic Algorithm.

Critical Impact
Attackers can reconstruct Fernet keys used to protect stored credentials, exposing API keys and authentication tokens for connected services.

Affected Products

IBM Langflow OSS 1.0.0 through 1.10.3
Deployments using user secrets shorter than 32 characters
Environments storing API keys and authentication tokens via Langflow's secret management

Discovery Timeline

2026-08-05 - CVE-2026-8470 published to the National Vulnerability Database
2026-08-05 - Last updated in NVD database

Technical Details for CVE-2026-8470

Vulnerability Analysis

IBM Langflow OSS generates Fernet symmetric encryption keys to protect sensitive data at rest, including third-party API keys and authentication tokens. When a user provides a secret shorter than 32 bytes, the application pads or derives the key material using Python's standard random module instead of secrets or another cryptographically secure source. The resulting Fernet key is therefore predictable whenever the seed value is known or guessable.

The Mersenne Twister algorithm is deterministic by design. Given the same seed, it emits the same sequence of values on every run. Attackers who obtain or brute-force the original short secret can replay the derivation routine locally and recover the exact Fernet key used by the target instance. Once the key is reproduced, all data encrypted with that key can be decrypted offline.

Root Cause

The root cause is the misuse of a non-cryptographic PRNG for key derivation. Python's random module documentation explicitly warns against security use. Combining this with a low-entropy input (secrets under 32 characters) collapses the effective key space to whatever entropy the user secret contains.

Attack Vector

The attack requires the adversary to learn or predict the short user secret used to seed key derivation. Sources include configuration files, environment variables leaked through logs, container image layers, or targeted brute-force against weak secrets. With the seed in hand, the attacker runs the same derivation logic and decrypts exfiltrated ciphertext without further interaction with the Langflow server.

See the IBM Support Page for vendor technical details.

Detection Methods for CVE-2026-8470

Indicators of Compromise

Access to Langflow configuration files, .env files, or container images by unauthorized users or processes
Outbound requests originating from services whose API keys are stored inside Langflow, without corresponding legitimate workflow execution
Log entries showing repeated read operations against Langflow's encrypted secret store

Detection Strategies

Inventory all Langflow OSS deployments and identify instances configured with user secrets shorter than 32 characters
Audit stored secrets and rotate any API keys or tokens that were encrypted by an affected version
Correlate access to Langflow secret storage with process, user, and network telemetry to identify anomalous readers

Monitoring Recommendations

Alert on unauthorized reads of Langflow database files, configuration files, and environment variable dumps
Monitor egress from third-party services whose credentials Langflow manages, watching for use from unexpected source addresses
Track version metadata across Langflow deployments to flag any host still running 1.0.0 through 1.10.3

How to Mitigate CVE-2026-8470

Immediate Actions Required

Upgrade IBM Langflow OSS to a fixed release as referenced on the IBM Support Page
Replace any user secret shorter than 32 characters with a high-entropy value of at least 32 bytes
Rotate every API key, authentication token, and credential that was stored in an affected Langflow instance

Patch Information

IBM has published remediation guidance on the IBM Support Page. Administrators should apply the vendor-supplied fixed version, which replaces the insecure key derivation path with a cryptographically secure routine.

Workarounds

Configure Langflow with a secret of 32 or more bytes generated by a cryptographically secure source such as python -c "import secrets; print(secrets.token_urlsafe(32))"
Restrict filesystem and container access so only the Langflow service account can read configuration and secret storage
Store the master secret in an external key management system rather than local configuration files

bash

# Generate a 32-byte high-entropy secret and export it before starting Langflow
export LANGFLOW_SECRET_KEY="$(python -c 'import secrets; print(secrets.token_urlsafe(32))')"