Cyber Resilience

CVE-2026-55450

CriticalPublic PoCDDoS

Published: 23 June 2026

Published
23 June 2026
Modified
24 June 2026
KEV Added
Patch
CVSS Score v3.1 9.3 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:N/A:H
EPSS Score 0.0031 22.8th percentile
Risk Priority 70 floored blend · peak EPSS

Summary

CVE-2026-55450 is a critical-severity Exposure of Sensitive Information to an Unauthorized Actor (CWE-200) vulnerability in Langflow Langflow. Its CVSS base score is 9.3 (Critical).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 22.8th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability details

Langflow is a tool for building and deploying AI-powered agents and workflows. Prior to 1.9.1, unauthenticated users can upload any amount of data to the server without any limitations. No need for any prior knowledge, only network access to Langflow.…

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This can lead to space exhaustion on the server. In addition, in the response, the absolute path of the uploaded file is reported to the attacker, which is an information leak that can assist in chaining other primitives. This vulnerability is fixed in 1.9.1.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
T1499.004 Application or System Exploitation Impact
Adversaries may exploit software vulnerabilities that can cause an application or system to crash and deny availability to users.
Why these techniques?

Unauthenticated upload to public-facing app enables T1190; resulting disk space exhaustion via exploitation enables T1499.004.

Confidence: HIGH · MITRE ATT&CK Enterprise v19.0

Affected Assets

langflow
langflow
≤ 1.9.1

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-200 CWE-306

Session auditing enables detection of unauthorized exposure or access to sensitive information during user activities.

addresses: CWE-200 CWE-400

Audit record review and analysis can detect unauthorized exposure or access to sensitive information.

addresses: CWE-200 CWE-400

The integrated analysis team enables faster detection and containment of incidents involving unauthorized exposure of sensitive information, limiting attacker success in exploiting such weaknesses.

addresses: CWE-200 CWE-306

Privacy and security architectures require controls to protect sensitive information from unauthorized exposure across the system lifecycle.

addresses: CWE-200 CWE-306

Inventory identifies all systems holding or processing data, enabling detection of unauthorized exposure paths before exploitation.

addresses: CWE-306 CWE-200

Protection planning for critical infrastructure directly calls for authentication of access to essential functions before any operation is permitted.

addresses: CWE-306 CWE-200

Risk assessments evaluate exposure of critical functions lacking authentication and prioritize corrective controls.

addresses: CWE-306 CWE-200

Requires authentication gates on critical functions that must remain unavailable to anonymous public users.

References