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

CVE-2026-55255 + Langflow Authorization Bypass Through User-Controlled Key Vulnerability + High + 2026-07-07

One-sentence business risk

This is in CISA KEV, so exposed deployments can become an audit and incident-response emergency with mandatory remediation timelines.

Research notes

  • Root cause: Langflow Authorization Bypass Through User-Controlled Key Vulnerability.
  • Affected versions: Langflow Langflow.
  • Fixed / safe versions: Apply mitigations or fixed release per vendor/CISA KEV instructions.
  • Public exploit / PoC signal: CISA KEV lists exploitation in the wild; prioritize emergency remediation.
  • CVSS: use upstream advisory score .

Exact vulnerable code pattern

run("tool " + user_controlled_value)

Fixed / mitigated code pattern

run(["tool", user_controlled_value], shell=False) with an allowlisted argument schema

Dependency or runtime update:

rg -n "affected component|CVE-2026-55255" .
# update affected runtime/product to Apply mitigations or fixed release per vendor/CISA KEV instructions

Step-by-step integration guide

  1. Inventory affected component across source, lockfiles, SBOMs, container images, CI images, and deployment manifests.
  2. Upgrade to Apply mitigations or fixed release per vendor/CISA KEV instructions or apply the exact vendor patch referenced below.
  3. Replace the vulnerable command-injection pattern with the fixed pattern and fail closed on malformed input.
  4. Add a regression test that exercises the advisory trigger and proves the request is rejected, bounded, or authorized.
  5. Deploy through canary, monitor security logs and resource metrics, then remove temporary edge blocks only after all runtimes are fixed.

Alternative mitigations

  • Disable the vulnerable feature path while the package/runtime update rolls out.
  • Add WAF or reverse-proxy rules for traversal tokens, prototype-polluting keys, oversized frames, shell metacharacters, or unauthenticated tool calls matching the trigger class.
  • Restrict internal egress, rotate exposed secrets, and revoke affected tokens/keys if the vulnerability can disclose config, logs, JWT secrets, proxy credentials, or PKI material.
  • For admin/API authorization issues, temporarily require elevated roles and explicit ownership checks at the gateway.

Detection signature

id: cve-2026-55255-langflow-authorization-bypass-through-user-contr
source: "CISA KEV"
dependency_or_product: "affected component"
affected: "Langflow Langflow"
fixed: "Apply mitigations or fixed release per vendor/CISA KEV instructions"
signals:
  - "command-injection"
  - "../"
  - "__proto__"
  - "tools/call"
  - "wp_ajax_nopriv"
  - "pickle.loads"
  - "shell command construction"
action: "upgrade, add regression test, and verify deploy artifact"

Copy-paste skill

You are remediating CVE-2026-55255 (Langflow Authorization Bypass Through User-Controlled Key Vulnerability) in this repository.

Find every affected dependency, runtime, image, service configuration, and reachable code path. Upgrade or patch to Apply mitigations or fixed release per vendor/CISA KEV instructions. Replace the vulnerable command-injection pattern with a fail-closed implementation, add a regression test for the trigger shape, and update deployment/SBOM artifacts. If this repository does not control the affected runtime, create TRIAGE.md naming the owner, affected version, fixed version, and blocking decision.

Keywords, affected tech stack, and revenue tags

  • Keywords: CVE-2026-55255, command-injection, affected component, CISA KEV.
  • Affected tech stack: general.
  • Revenue tags: sellable_to_fintech, enterprise_blocker, high_priority_sla.

References