Is CVE-2026-55450 actively exploited?

Yes. KEV Intelligence has observed exploitation attempts targeting this CVE. Confidence is confirmed.

What exploitation activity has KEV Intelligence observed?

KEV Intelligence sensors have observed 4 exploitation attempts, 3 unique attacker IPs, and 3 countries targeting CVE-2026-55450. First observed Aug 08, 2026; last observed Aug 12, 2026.

Which versions are affected?

CVE-2026-55450 affects langflow-ai langflow. Reported affected version: < 1.9.1.

How should organizations remediate it?

Prioritize immediate patching and validate internet-facing exposure. Monitor for matching exploitation attempts in your environment.

No. CVE-2026-55450 is not currently listed in CISA KEV.

Vulnerability report

Active exploitation observed Confirmed confidence Not in CISA KEV

CVE-2026-55450

Q: How should organizations remediate it?

Prioritize immediate patching and validate internet-facing exposure. Monitor for matching exploitation attempts in your environment.

Q: Is it in CISA KEV?

No. CVE-2026-55450 is not currently listed in CISA KEV.

langflow Denial of Service

langflow-ai / langflow · affected before 1.9.1

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Severity: CVSS 9.3 · Critical
Confidence: Confirmed
Exploit status: Observed in sensors
EPSS: 11.8%
First observed: 08 Aug 2026
Last observed: 12 Aug 2026

Decision summary

What security teams need to know first

Direct answers before the deeper technical record.

What it is

CVE-2026-55450 is an unauthenticated vulnerability affecting langflow-ai langflow. Langflow is a tool for building and deploying AI-powered agents and workflows. Prior to 1.9.1, unauthenticated users can upload any...

Is it exploited?

Yes. KEV Intelligence sensors observed exploitation attempts with confirmed confidence.

Who is affected?

langflow-ai / langflow affected before 1.9.1.

What should we do?

Patch immediately, validate internet-facing exposure, and monitor for matching requests.

Overview

Langflow is a tool for building and deploying AI-powered agents and workflows

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.

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.

Vendor Product Affected Status

langflow-ai langflow Before 1.9.1 Affected

Published: 23 Jun 2026
Exploitation Reported: 08 Aug 2026
Attack vector: Remote
Complexity: Low
Privileges: None
User interaction: None

CVE References

CVE Record CVE.org · CVE Record https://www.cve.org/CVERecord?id=CVE-2026-55450
https://github.com/langflow-ai/langflow/security/advisories/GHSA-x223-p2gf-v735 github.com · CVE Record https://github.com/langflow-ai/langflow/security/advisories/GHSA-x223...
https://github.com/langflow-ai/langflow/pull/12831 github.com · CVE Record https://github.com/langflow-ai/langflow/pull/12831

Exploitation evidence

Why KEV Intelligence marks this CVE as exploited

Third-party attestation and first-party sensor observation are shown separately so teams can judge the evidence chain.

Exploited in the wild

KEV Intelligence

Recorded 08 Aug 2026

Independent exploitation attestation added to the KEV Intelligence record.

Active exploitation observed

KEV Intelligence sensor

First observed 08 Aug 2026

First-party sensor telemetry confirms matching exploitation attempts.

Proof of concept available

Nuclei Templates

Recorded 01 Aug 2026

Public scanner or PoC coverage increases practical exploitability.

Known exploited vulnerability sources

Per-source evidence links for KEV attestations are available through the KEV Intelligence Pro API.

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Source	Added
KEV Intelligence First	2026-08-09 12:09 UTC

Operational indicators for this CVE are listed under Detection.

Sensor telemetry

First-party evidence of exploitation activity

Aggregate observations show the scale, recency, and distribution of activity without overstating sparse data.

Attempts observed

Unique attacker IPs

Attacker countries

FR · NL · US

Sensors observed

Exploitation attempts over the last 13 days

Daily events observed by KEV Intelligence sensors

Updated 19 Aug 2026

7 Aug 10 Aug 13 Aug 16 Aug 19 Aug

First observed 08 Aug 2026 · Last observed 12 Aug 2026

Pro adds sensor region and window summaries. Enterprise adds raw IPs, paths, User-Agents, and payloads.

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Detection

Operational artifacts and observed signals

Make the evidence actionable in scanner, SOC, and edge-control workflows.

Observed signals

Request targets: 1
User-Agents: 4

Raw values available in Pro and Enterprise.

Scanner coverage

Nuclei template detected 01 Aug 2026.

View Nuclei template

Virtual patch status

No KEV Intelligence virtual patch is currently available. Future rules ship for ModSecurity, Cloudflare, and AWS WAF.

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Attacker IP Indicators

Attacker IP indicators observed · available in Pro and Enterprise.

Sensor-derived attacker IP indicators are available to Pro and Enterprise accounts under Detection and through the Pro API.

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Scanner Artifacts

Scanner and exploit-framework references linked to this CVE.

Scanner	Reference	Detected
Nuclei	https://github.com/projectdiscovery/nuclei-templates/blob/main/http/cves/2026/CVE-2026-55450.yaml	01 Aug 2026

Risk and context

Severity, weaknesses, and research context

CVSS v3.1

9.3 Critical

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

EPSS

11.8%

Weaknesses

Exposure of Sensitive Information to an Unauthorized Actor CWE-200 Missing Authentication for Critical Function CWE-306 Uncontrolled Resource Consumption CWE-400

Potential Proof of Concepts

These PoCs are unverified and could contain malware. Use at your own risk.

Langflow < 1.9.1 - Unauthenticated File Upload

nuclei · Created Unknown

Timeline

From disclosure to observed exploitation

08 Aug 2026
Observed by KEV Intelligence sensors

Evidence-backed exploitation signal
08 Aug 2026
Indicators of compromise added (3)

Indicators of compromise recorded
01 Aug 2026
Public PoC available

Public proof-of-concept code published
01 Aug 2026
Nuclei template available

Scanner coverage available
23 Jun 2026
CVE published

Vulnerability disclosed publicly
16 Jun 2026
CVE ID reserved

Identifier reserved by the CNA

Pro API

Automate this intelligence

Confidence, exploit status, sensor telemetry, PoCs, scanner integrations, mentions, and tags are available programmatically for VM, SOC, and CTI workflows.

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Evidence confidence and provenance
First-party sensor telemetry
PoC and scanner references
Affected versions and enrichment
Automation-ready JSON delivery

GET /api/v2/pro/kevs/CVE-2026-55450

Free JSON includes basic KEV fields

{
  "cve_id": "CVE-2026-55450",
  "confidence": "Confirmed",
  "cvss_score": 9.3,
  "cvss_estimated": false,
  "epss_score": 0.11819,
  "exploit_status": {
    "exploited_in_the_wild": true,
    "active_exploitation_observed": true
  },
  "sensor_telemetry": { "attempts": 4, "sensors": 2 }
}

Early warning alerts

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