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Vulnerability Intelligence

CVE-2026-55255

HighExploitedPublic exploit

Langflow: IDOR Vulnerability in /api/v1/responses Endpoint Allows Authenticated Attackers to Access Another User's Flow

Published Jun 19, 2026 · Updated Oct 9, 2026 · Also known as GHSA-qrpv-q767-xqq2, PYSEC-2026-221, ROOT-APP-PYPI-CVE-2026-55255

Key Facts

Patch immediately
  • CVE-2026-55255 is a high-severity vulnerability (CVSS 8.4 v3.1) affecting Langflow, rootio-langflow.
  • It is exploited in the wild, listed in CISA KEV, Industry KEV feed, CIRCL KEV, ENISA EUVD since Jun 26, 2026. Public exploit code is available.
  • EPSS estimates a 0.9% probability of exploitation in the next 30 days.
  • Fixed versions are available, including Langflow 1.6.0+aikido.2, Langflow 1.6.9+aikido.3, Langflow 1.7.0+aikido.2.
  • Brandefense priority: patch immediately, because it is listed as exploited in the wild.

CVSS v3.1

8.4

CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:L

EPSS (30-day exploit likelihood)

0.9%

Higher than 58.5% of all scored CVEs

Exploited in the wild

Yes

4 catalog listings

Public exploit code

Available

Proof-of-concept or weaponized module

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Description

Langflow is a tool for building and deploying AI-powered agents and workflows. Prior to 1.9.1, an Insecure Direct Object Reference (IDOR) vulnerability in /api/v1/responses endpoint allows an authenticated attacker to execute any flow belonging to another user by specifying the victim's flow ID in the request. This vulnerability is fixed in 1.9.1.

Known-Exploited Catalog Listings

CatalogAddedRemediation dueRansomware use
CISA KEVJul 7, 2026Jul 10, 2026Not reported
Industry KEV feedJun 26, 2026Jul 10, 2026Not reported
CIRCL KEVJul 7, 2026Jul 10, 2026Not reported
ENISA EUVDJul 7, 2026n/aNot reported

Required action: Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.

Affected Products

5 affected entries in total
ProductAffected versionsFixed in
LangflowLangflow>= < 1.9.21.9.2
rootio-langflowrootSee advisory1.9.0+root.io.2

Patched Releases

Langflow

1.6.0+aikido.2, 1.6.9+aikido.3, 1.7.0+aikido.2, 1.7.3+aikido.2, 1.8.1+aikido.2, 1.8.4+aikido.2, 1.9.0+aikido.2, 1.9.0+aikido.3, 1.9.1, 1.9.2

rootio-langflow

1.6.0+root.io.2, 1.6.9+root.io.3, 1.7.0+root.io.2, 1.7.3+root.io.2, 1.8.1+root.io.2, 1.8.4+root.io.2, 1.9.0+root.io.2

Timeline

  1. Publicly disclosed

    Jun 19, 2026

  2. Added to Industry KEV feed

    Jun 26, 2026

  3. Added to CISA KEV

    Jul 7, 2026

  4. Added to CIRCL KEV

    Jul 7, 2026

  5. Added to ENISA EUVD

    Jul 7, 2026

  6. Last updated

    Oct 9, 2026

Weakness Type

  • CWE-639 Authorization Bypass Through User-Controlled Key

References

12 more references in the full CVE brief

FAQ

Common Questions.

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