CVE-2026-9205 is a weak key derivation flaw in the ensure_fernet_key() function of IBM Langflow OSS, rated 7.4 (high). IBM lists versions 1.0.0 through 1.10.3 as affected and recommends Langflow OSS 1.11.0 or newer. There is no workaround, so upgrade and consider rotating stored secrets.
What's affected
- Product: Langflow OSS, the open source tool for building AI workflows.
- Affected: versions 1.0.0 through 1.10.3, per IBM's bulletin.
- Fixed: Langflow OSS 1.11.0 or newer.
- Workarounds: IBM lists none.
- The same IBM bulletin covers other Langflow issues, including CVE-2026-8470, CVE-2026-10128 and CVE-2026-17629, so one upgrade handles the group.
How to check if you're exposed
Check the installed version in each environment where Langflow runs:
pip show langflow
docker ps --format '{{.Image}}' | grep -i langflow
Anything from 1.0.0 through 1.10.3 is in scope. Also note how your instance's secret key was set. The related entry CVE-2026-8470 in the same bulletin says keys built from user secrets shorter than 32 characters were derived with a predictable generator.
What to do now
- Upgrade Langflow OSS to 1.11.0 or newer.
- Set a long, random secret key of your own rather than relying on a short one.
- After upgrading, rotate API keys and tokens that Langflow stored, because data protected by a weak key should be treated as exposed if the database or backups leaked.
- Restrict network access to Langflow and keep its database and backups private.
- Review IBM's bulletin for the other CVEs and confirm your version clears all of them.
Why it matters
The record lists CWE-338, use of a cryptographically weak pseudo-random number generator. Fernet keys protect secrets such as stored API keys. If the key can be reproduced from predictable inputs, the encryption stops doing its job for anyone who can get hold of the encrypted data.
The vector is network based with high attack complexity and no privileges, and scores high for confidentiality and integrity. The record does not mark this CVE as exploited in the wild.
Quick check
Is upgrading enough?
The upgrade fixes how new keys are derived. Secrets already stored under a weak key were protected by it, so rotate them to be safe.
Sources
Last reviewed: 19 October 2026.
