CVE-2026-55450
CriticalExploitedPublic exploitLangflow: Unauthenticated file upload leads to DoS (space exhaustion) and information leak
Published Jun 17, 2026 · Updated Aug 12, 2026 · Also known as GHSA-x223-p2gf-v735, PYSEC-2026-224
Key Facts
Patch immediately- CVE-2026-55450 is a critical-severity vulnerability (CVSS 9.3 v3.1) affecting Langflow.
- It is exploited in the wild, listed in Industry KEV feed, CIRCL KEV since Aug 9, 2026. Public exploit code is available.
- EPSS estimates a 1.2% probability of exploitation in the next 30 days.
- Fixed versions are available, including Langflow 1.9.1.
- Brandefense priority: patch immediately, because it is listed as exploited in the wild.
CVSS v3.1
9.3
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:N/A:H
EPSS (30-day exploit likelihood)
1.2%
Higher than 67.4% of all scored CVEs
Exploited in the wild
Yes
2 catalog listings
Public exploit code
Available
Proof-of-concept or weaponized module
Get the full CVE-2026-55450 brief as a PDF
Every affected product and fixed release, exploitation status and a first 24 hours response checklist, emailed within minutes.
Description
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.
Known-Exploited Catalog Listings
| Catalog | Added | Remediation due | Ransomware use |
|---|---|---|---|
| Industry KEV feed | Aug 9, 2026 | n/a | Not reported |
| CIRCL KEV | Aug 9, 2026 | n/a | Not reported |
Required action: Apply remediations or mitigations per vendor instructions or discontinue use of the product if remediation or mitigations are unavailable.
Affected Products
3 affected entries in total| Product | Affected versions | Fixed in |
|---|---|---|
| LangflowLangflow | >= < 1.9.1 | 1.9.1 |
Patched Releases
Langflow
1.9.1
Timeline
Publicly disclosed
Jun 17, 2026
Added to Industry KEV feed
Aug 9, 2026
Added to CIRCL KEV
Aug 9, 2026
Last updated
Aug 12, 2026
Weakness Type
- CWE-200 Exposure of Sensitive Information to an Unauthorized Actor
- CWE-306 Missing Authentication for Critical Function
- CWE-400 Uncontrolled Resource Consumption
References
- advisoryGHSA advisory
- advisoryhttps://github.com/CVEProject/cvelistV5/tree/main/cves/2026/55xxx/CVE-2026-55450.json
- advisoryhttps://github.com/langflow-ai/langflow/pull/12831
- advisoryhttps://github.com/langflow-ai/langflow/security/advisories/GHSA-x223-p2gf-v735
- advisoryhttps://nvd.nist.gov/vuln/detail/CVE-2026-55450
FAQ
Common Questions.
Langflow is a tool for building and deploying AI-powered agents and workflows.
Affected: Langflow versions >= < 1.9.1. The full list is in the CVE brief.
It is exploited in the wild, listed in Industry KEV feed, CIRCL KEV since Aug 9, 2026.
No, it is not currently listed in the CISA Known Exploited Vulnerabilities catalog.
Public exploit code is available.
Fixed versions are available, including Langflow 1.9.1.
Brandefense priority: patch immediately, because it is listed as exploited in the wild.
Is CVE-2026-55450 Running On Your Attack Surface?
Brandefense maps vulnerabilities like this one to your internet-facing assets and tells you exactly where to patch.
Request A Demo