high CVSS 8.8

CVE-2026-9201·Python vulnerability

IBM Langflow OSS 1.0.0 through 1.10.3 could allow an authenticated attacker to execute arbitrary code due to a cryptographic weakness in the custom component validation mechanism. When the optional hardening mode that restricts execution to trusted component templates is enabled, the application validates component code using a truncated SHA‑256 hash. Because the hash comparison relies on only a portion of the digest, an attacker can craft malicious component code that collides with a trusted template hash and bypasses validation. Successful exploitation allows the attacker to introduce and execute unauthorized Python code within the Langflow process, defeating the intended security control and potentially leading to full compromise of the affected instance.

Severity
high
Software
Python
Fixed in
1.11.0
Published
2026-08-05

Affected versions

From: 1.0.0

Until: 1.11.0

Fixed in: 1.11.0

How to fix this CVE

Upgrade IBM Langflow OSS to version 1.11.0 or later to remediate the hash collision vulnerability in the component validation mechanism. This update replaces the truncated SHA-256 hash comparison with a complete hash validation, preventing attackers from crafting malicious components that bypass trusted template verification. Ensure all instances of Langflow in your environment are patched to eliminate the risk of arbitrary code execution.

sudo dnf update python3-langflow

Defensia detects this vulnerability

How to check if you are affected

  1. Check the installed Langflow version: pip show langflow | grep Version
  2. Verify if hardening mode is enabled in your Langflow configuration: grep -i 'hardening\|trusted_component' /path/to/langflow/config.yaml or environment variables
  3. Search application logs for unexpected component validation errors or code execution from untrusted sources: grep -i 'component.*validation\|hash.*mismatch' /var/log/langflow/*.log
  4. Confirm the patch is applied by re-running pip show langflow and verifying the version is 1.11.0 or higher

FAQ

What is CVE-2026-9201?

CVE-2026-9201 is a cryptographic weakness in IBM Langflow OSS's component validation mechanism that allows authenticated attackers to bypass hash-based security controls by exploiting truncated SHA-256 comparisons, enabling arbitrary Python code execution within the Langflow process.

Is CVE-2026-9201 being actively exploited?

No, CVE-2026-9201 is not currently listed on the CISA Known Exploited Vulnerabilities (KEV) catalog and no public exploits have been disclosed at this time.

What versions of Langflow are affected by CVE-2026-9201?

IBM Langflow OSS versions 1.0.0 through 1.10.3 are vulnerable. Version 1.11.0 and later contain the fix.

How do I check if my server is vulnerable to CVE-2026-9201?

Run 'pip show langflow | grep Version' and check if the version is between 1.0.0 and 1.10.3; if so, your instance is vulnerable. Additionally, verify that hardening mode is enabled in your Langflow configuration to determine exposure risk.

Does Defensia detect CVE-2026-9201?

Yes — Defensia's CVE advisory scanner compares installed package versions against the NVD database. If Langflow is installed on a monitored server, CVE-2026-9201 will appear in your dashboard with remediation steps.

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References

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