CVE-2026-55450

CRITICAL 9.3 PoC AVAILABLE

Published 2026-06-23 · Last modified 2026-06-23

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.

EXPLOIT AVAILABLE

Public exploit or PoC code exists. Modeled probability is still low, but the barrier to attack is reduced — watch closely.

Exploitation likelihood

0.3%chance of exploitation in 30 days · 25th percentile

○ In CISA KEV ● Public exploit / PoC

Impact if exploited

9.3CVSS 3.1 · CRITICAL

ConfidentialityLow
IntegrityNone
AvailabilityHigh

What an attacker needs

✓Access: Reachable over the network — no local access needed
✓Privileges: No account or privileges required
✓User interaction: No user interaction needed
✓Complexity: No special conditions — reliably repeatable

✓ lowers the bar for an attacker · ⚠ raises it

Proof of concept & exploit code

reference https://github.com/langflow-ai/langflow/security/advisories/GHSA-x223-p2gf-v735
github-search Search GitHub for public PoC repos

Test against your own equipment

curl -s https://vulnpedia.com/cve/CVE-2026-55450/poc.jsonMachine-readable PoC index for this CVE (for automation).

Listed for defensive triage, patch verification, and authorized testing on systems you own. Machine-readable: /cve/CVE-2026-55450/poc.json

Affected

Vendors Langflow Ai Langflow

Products Langflow

Weakness (CWE)

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

CVSS vector

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

Known Affected Software Configurations

Vendor	Product	Version range
Langflow	Langflow	< 1.9.1

All CVSS metrics

CRITICAL 9.3 v3.1 · CNA Primary
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:N/A:H
CRITICAL 9.3 v3.1 · NVD Secondary
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:N/A:H

References

Exploits & PoC

https://github.com/langflow-ai/langflow/security/advisories/GHSA-x223-p2gf-v735 x_refsource_CONFIRMexploitExploitPatchVendor Advisory

Patches & mitigations

https://github.com/langflow-ai/langflow/pull/12831 x_refsource_MISCIssue TrackingPatch

Sources: NVD · CVE.org · EPSS