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Change Risk Intel
CVE tracker

CVE-2026-55255 — Langflow Authorization Bypass Through User-Controlled Key Vulnerability

Langflow contains an authorization bypass through user-controlled key vulnerability which allows an authenticated attacker to execute any flow belonging to another user by specifying the victim's flow ID in the request.

CVSS
8.1 (High)
KEV status
CISA KEV — Listed
First seen (CISA KEV)
Recommended change window
Emergency change — upgrade Langflow to the fixed release the same day; every tenant on a shared instance is exposed.
Vendor advisory
https://github.com/langflow-ai/langflow/security/advisories/GHSA-qrpv-q767-xqq2
Affected products
Langflow Langflow

Why this one matters to a CAB

Langflow is an AI application builder — flows contain LLM API keys, retrieval-augmented-generation source URIs, and often downstream service tokens. An authenticated attacker who can execute another tenant’s flow inherits that tenant’s secrets and downstream reach. In a shared-instance deployment, this is a multi-tenant blast radius.

Defender’s angle

  • Tenant isolation review: if your Langflow instance is multi-tenant, this CVE is the trigger to move to per-tenant containers or a dedicated instance per business unit.
  • Secret rotation: any API key, model provider token, or database credential referenced by a Langflow flow during the exposure window should be rotated. Do not assume containment.
  • Audit trail: enable Langflow’s audit log before restoring service. The default logging misses POST /api/v1/run/{flow_id} parameters that are exactly what you need for post-incident attribution.

What to bring to CAB

A change record that is really a two-part deliverable: (1) upgrade Langflow to the fixed version, (2) enumerate and rotate every secret referenced by any flow on the instance. Sign-off requires both.

Sources

This page summarizes publicly available information from CISA KEV, NVD, and the listed vendor advisory. Change Risk Intel does not publish exploit walkthroughs. Verify with your vendor before scheduling any change window.