CVE-2026-18899 Path traversal in Langflow OSS

What is CVE-2026-18899?

CVE-2026-18899 is a high-severity path traversal vulnerability in Langflow Langflow, published on 28 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

IBM Langflow OSS 1.0.0 through 1.11.1 could allow a remote attacker to read arbitrary files due to path traversal.

Weakness: CWE-22

Which versions are affected by CVE-2026-18899?

It affects 1 product.

Products include Langflow Langflow.

How do I fix CVE-2026-18899?

No fix has been published for CVE-2026-18899 yet. Limit exposure of the affected software until one is available.

Upgrade, and resolve every user-supplied path against an allowed base folder before opening it. More about Path traversal.

Is CVE-2026-18899 being exploited?

There is no known exploitation of CVE-2026-18899 in the wild and no public exploit code.

Other vulnerabilities in Langflow Langflow

• CVE-2026-9198 IBM Langflow Code Injection Exploited Critical 9.8
• CVE-2026-0770 Langflow Inclusion of Functionality from Untrusted Control Sphere Exploited Critical 9.8
• CVE-2025-3248 Langflow Missing Authentication Exploited Critical 9.8
• CVE-2025-34291 Langflow Origin Validation Error Exploited Critical 9.4
• CVE-2026-33017 Langflow Code Injection Exploited Critical 9.3

All Langflow Langflow vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as GHSA-4w6q-3qxv-hmwg.