CVE-2026-19306: IBM Langflow OSS 1.0.0 through 1.11.2 allows an authenticated attacker to read arbitrary files from the server filesystem

IBM Langflow OSS 1.0.0 through 1.11.2 allows an authenticated attacker to read arbitrary files from the server filesystem — including server secret material (se

IBM Langflow OSS 1.0.0 through 1.11.2 allows an authenticated attacker to read arbitrary files from the server filesystem — including server secret material (secret_key, JWT signing keys, the application database, /proc/self/environ, and other tenants' upload directories) — by supplying absolute paths or traversal sequences in the files parameter of an authenticated build request. The file contents were embedded as text attachments in the language model prompt and transmitted to the configured model endpoint, resulting in confidential data exfiltration. This bypassed the LANGFLOW_RESTRICT_LOCAL_FILE_ACCESS=true containment boundary, which was enforced for other file-reading components but not for the Chat Input to Message attachment pipeline.

Description from the National Vulnerability Database, published by psirt@us.ibm.com

What it means for a small business

If your business uses Langflow OSS, install the vendor's update. If you're not sure whether you use it, ask whoever manages your computers.

How likely is an attack? The Exploit Prediction Scoring System, run by FIRST (the global association of security response teams), puts the odds of this one being exploited in the next 30 days at 0.54%, higher than 45% of CVEs. That’s low, but low isn’t zero, and the odds jump the day someone publishes an exploit. Scored October 28, 2026, updated daily.

Check your own setup

Website check: reads what your site runs from the outside (WordPress version, plugins it can see, old server software) and matches it against this database.
Server check: what your web server says about itself, and whether that version has known flaws.

Sources

Part of the Huttenlocher Technologies vulnerability database, refreshed twice a day from CISA and the NVD. The title, category and plain-language guidance are ours; check the linked record before acting on a detail. This is general guidance, not a review of your systems.

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