CVE-2026-77819

Langflow path traversal allows file overwrite

IBM / Langflow · Langflow OSS

First documented disclosure · Review checkpoint

Summary

Overwrite of files writable by the service; a complete code-execution chain is not established.

Severity and exploitation evidence

Medium · 6.5/10 · CVSS 3.1. Severity source.

Exploitation not established: The reviewed primary records do not establish malicious exploitation or a confirmed victim.

Exploitation evidence source

Technical severity is not a measure of observed attacks or of risk to your deployment. Attempts, demonstrations, and successful compromise retain the qualifications in the source.

How the weakness works

A write path is not confined to its intended directory; the exact handler is not publicly specified.

Conditions required

Remote authenticated access to the affected file-write feature.

Potential impact

Overwrite of files writable by the service; a complete code-execution chain is not established.

Affected versions and configurations

IBM lists Langflow OSS 1.0.0 through 1.12.3.

Fix and mitigation status

1.12.4 per IBM; this is an issue-specific fix, not assurance that the old release addresses later findings.

Practical next steps

Upgrade to a current supported release containing the fix; back up the deployment and validate workflow behavior.

Operating lesson

Validate the final write path and isolate writable workflow storage.

Evidence and limits

IBM bulletin 7293015 was initially published 2026-10-19; the CNA record followed on 2026-10-29. Earlier upstream patches are not assigned to this CVE by inference. Exact technical details absent from the public record remain unknown; a CVSS score is not an observed incident.

Sources