CVE-2026-55255 CISA KEV · Actively exploited

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

CVSS score

8.4

EPSS probability

%0.9

Risk score

0.1

Published

3 mo ago

Overview Public Exploits (0)Newsroom Vulnerability Timeline

Official patch verified

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Impact on My Inventory

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Vulnerability description

DayBreach CVE AI Research

CVE-2026-55255 has vendor, distribution, patch and security-source records on file. We can compare them and prepare an explanation linked to the evidence.

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.

IMPACT: Affected Products and Software

Affected Products

The following products are affected by CVE-2026-55255 vulnerability. Where our threat engine knows the exact affected versions, they are listed below.

ID	VENDOR	PRODUCT	ACTION
1	langflow-ai	langflow	View
2	langflow	langflow	View

Total affected vendors: 2|Products: 2

RED HAT CSAF/VEX: Product Impact Check

Red Hat has not yet published a CSAF/VEX impact record for this CVE. This does not mean “not affected”.

SCORING: CVSS from Multiple Sources

CVSS Scores

The Common Vulnerability Scoring System is a standardised framework for assessing the severity of vulnerabilities in software and systems. We collect and display CVSS scores from several sources for each CVE.

SCORE	VERSION	SEVERITY	VECTOR	SOURCE
8.4	CVSS V31	HIGH	CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:L	NVD
8.4	CVSS V3_1	HIGH	CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:L	CVE CNA

Patch and Remediation Guide

Solution & Remediation Advisory

Patch verified

2 doğrulanmış yama veya düzeltilmiş sürüm kanıtı bulundu.

nvd

NVD tarafından Patch olarak etiketlenmiş referans

Open source

nvd

NVD tarafından Patch olarak etiketlenmiş referans

Open source

canonical

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.

Confirm the affected product and version against the source evidence above.

Restrict access to internet-facing services and apply network segmentation.

Apply the official update named in the evidence only to the matching product and version.

Monitor server logs and network endpoints for signs of anomalous execution.

Public exploit and active exploitation status

Verified exploit intelligence

This CVE is marked as actively exploited in the CISA KEV catalogue, but no verified, downloadable public PoC or Metasploit module has been found yet. Evidence of active exploitation does not mean that public exploit code exists.

Weakness Classification and Attack Patterns (CWE & CAPEC)

CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorises the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-55255 is associated with the following CWEs:

CWE-639: Common Weakness Enumeration Entry CWE-639

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-55255 weaknesses.

CAPEC-66: SQL Injection CAPEC-126: Path Traversal CAPEC-28: OS Command Injection

Attack Vector and Accessibility

ExposureAğ üzerinden

PermissionsLow

UserGerekmiyor

Official Sources and Advisories

https://github.com/langflow-ai/langflow/security/advisories/GHSA-qrpv-q767-xqq2vendor-advisory https://github.com/langflow-ai/langflow/pull/12832vendor-advisory https://github.com/langflow-ai/langflow/commit/2c9f498d664a3c32698b57d7c5e752625291060evendor-advisory https://webflow.sysdig.com/blog/understanding-langflow-cve-2026-55255-and-why-higher-cvss-vulnerabilities-arent-always-the-most-exploitednvd https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-55255nvd CISA Known Exploited Vulnerabilities Catalogkev

CVSS Vector Radar Chart

8.4 / 10

Vulnerability Scoring Details

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

Attack VectorNetwork

Attack ComplexityHigh

Privileges RequiredLow privileges

User InteractionNone required

Confidentiality (Gizlilik)High

Integrity (Bütünlük)None

Availability (Erişilebilirlik)Low

Yama doğrulandı

2 doğrulanmış yama veya düzeltilmiş sürüm kanıtı bulundu.

Follow the vendor

langflow-ai

langflow

Weakness Type (CWE & CAPEC)

CWE-639

Similar Vulnerabilities

9.8

CVE-2025-3248 Actively exploited

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