CVE-2026-55255 (GCVE-0-2026-55255)

Vulnerability from cvelistv5 – Published: 2026-06-23 16:28 – Updated: 2026-07-08 03:56
VLAI CISA Previdian
Title
Langflow: IDOR Vulnerability in `/api/v1/responses` Endpoint Allows Authenticated Attackers to Access Another User's Flow
Summary
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.
Severity
8.4 (High)
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:L
SSVC
Exploitation: active Automatable: no Technical Impact: total
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-06-23 00:00 UTC
CWE
  • CWE-639 - Authorization Bypass Through User-Controlled Key
Assigner
References
Impacted products
Vendor Product Version CPE status
langflow-ai langflow Affected: < 1.9.1
guessed Create a notification for this product.
CISA
Known Exploited Vulnerability - GCVE BCP-07 Compliant
KEV entry ID: ee805f28-6d4c-4559-b398-87ff0a133ef0

Vulnerability ID: CVE-2026-55255

Status: Confirmed

Status Updated: 2026-07-07 00:00 UTC

Exploited: Yes

Timestamps
First Seen: 2026-07-07
Asserted: 2026-07-07
Scope
Notes: KEV entry: Langflow Authorization Bypass Through User-Controlled Key Vulnerability | Affected: Langflow / Langflow | Description: 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. | 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. | Due date: 2026-07-10 | Known ransomware campaign use (KEV): Unknown | Notes (KEV): https://github.com/langflow-ai/langflow/security/advisories/GHSA-qrpv-q767-xqq2 ; BOD 26-04: https://www.cisa.gov/news-events/directives/bod-26-04-prioritizing-security-updates-based-risk ; Forensics Triage Requirements: https://www.cisa.gov/news-events/directives/bod-26-04-implementation-guidance-prioritizing-security-updates-based-risk ; https://nvd.nist.gov/vuln/detail/CVE-2026-55255
Evidence

Type: Vendor Report

Signal: Successful Exploitation

Confidence: 80%

Source: cisa-kev

Details
Cwes CWE-639
Feed CISA Known Exploited Vulnerabilities Catalog
Product Langflow
Due Date 2026-07-10
Date Added 2026-07-07
Vendorproject Langflow
Vulnerabilityname Langflow Authorization Bypass Through User-Controlled Key Vulnerability
Knownransomwarecampaignuse Unknown
References
Created: 2026-07-07 18:00 UTC | Updated: 2026-07-07 18:00 UTC
Previdian
Known Exploited Vulnerability - GCVE BCP-07 Compliant
KEV entry ID: dd1e4271-1fb8-4dfa-af0f-1b755d41763d

Vulnerability ID: CVE-2026-55255

Status: Confirmed

Status Updated: 2026-07-07 17:00 UTC

Exploited: Yes

Timestamps
First Seen: 2026-07-07
Asserted: 2026-07-07
Scope
Notes: KEVIntel entry: Langflow: IDOR Vulnerability in `/api/v1/responses` Endpoint Allows Authenticated Attackers to Access Another User's Flow | Affected: langflow-ai / langflow | CVSS: 9.9 (CRITICAL) | EPSS: 0.00233 | Used in malware: unknown | Not yet in CISA KEV: False
Evidence

Type: Public Report

Signal: Successful Exploitation

Confidence: 70%

Source: kevintel

Details
Feed KEVIntel (kevintel.com)
Title Langflow: IDOR Vulnerability in `/api/v1/responses` Endpoint Allows Authenticated Attackers to Access Another User's Flow
Vendor langflow-ai
Product langflow
Added Date 2026-07-07T17:00:54.263Z
Cvss Score 9.9
Epss Score 0.00233
Cvss Severity CRITICAL
Epss Percentile 0.14148
Used In Malware unknown
Ahead Of Cisa Kev None
Not Yet In Cisa Kev False
References
Created: 2026-07-07 18:00 UTC | Updated: 2026-07-10 06:14 UTC
Show details on NVD website
To clipboard 

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Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

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Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
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  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.



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