NVD / CVE Program· CNA GitHub_M

CVE-2026-21445: Langflow Missing Authentication on Critical API Endpoints

Noroxi assessment

Priority: Plan (action score 45/100)

A ready-made attack module is public (Nuclei); exploiting it takes no special expertise.
Public proof-of-concept code exists (GitHub); there is no record of exploitation in the wild.
Probability of exploitation in the next 30 days: 33.2% (FIRST EPSS); higher than 98.3% of all records.
Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
According to CISA the attack is automatable: targets can be found by mass scanning.
Fixed version: langflow (PyPI) 1.7.1; langflow-base (PyPI) 0.7.1.

Add it to your regular patch cycle. Upgrade to langflow (PyPI) 1.7.1; langflow-base (PyPI) 0.7.1 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

Langflow is a tool for building and deploying AI-powered agents and workflows. Prior to version 1.7.0.dev45, multiple critical API endpoints in Langflow are missing authentication controls. The issue allows any unauthenticated user to access sensitive user conversation data, transaction histories, and perform destructive operations including message deletion. This affects endpoints handling personal data and system operations that should require proper authorization. Version 1.7.0.dev45 contains a patch.

HighCVSS 8.8 · v4.0—Proof of concept Fix available

Published: Jan 2, 2026
Updated: Jun 17, 2026
EPSS: 33.2% · 98th percentile
CWE: CWE-306

Report tools

JSON

Action score

Plan

Add it to your regular patch cycle.

CVSS: 35 / 40 · 8.8 / 10
CISA KEV: 0 / 30 · Not listed
EPSS: 10 / 30 · 33.2%

CISA SSVC decision

Exploitation: none
Automatable: yes
Technical impact: total

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD: —
CNA · GitHub_M: 8.8; NVD has not scored this yet; the score shown is the CNA’s.

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:P

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

Not in KEV: no record of exploitation in the wild
Proof of concept exists, no weaponized module
A fix has been released

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

Vendor	Product	CPE
langflow	langflow	cpe:2.3:a:langflow:langflow

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

langflow langflowbefore 1.7.1

Versions reported by the vendor

Affected version ranges reported by the assigning authority (GitHub_M). Independent of NVD's CPE analysis and usually ahead of it.

langflow-ai langflow
- < 1.7.0.dev45affected

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

Ecosystem	Package	Affected range	Fix
PyPI	langflow	before 1.7.1	1.7.1
PyPI	langflow-base	before 0.7.1	0.7.1

Same product

langflow: all records

Other highest-scoring records for the same primary product.

CVE-2025-3248Langflow < 1.3.0 Unauthenticated RCE via /api/v1/validate/codeKEV
99Now
CVE-2026-33017Langflow has Unauthenticated Remote Code Execution via Public Flow Build EndpointKEV
96Now
CVE-2025-34291Langflow <= 1.6.9 CORS Misconfiguration to Token Hijack & RCEKEV
95Now

Published before and after this one in the same product

← EarlierCVE-2025-68477Dec 19, 2025 · Langflow vulnerable to Server-Side Request Forgery
28Monitor
← EarlierCVE-2025-68478Dec 19, 2025 · Langflow Vulnerable to External Control of File Name or Path
30Monitor
Later →CVE-2026-0768Jan 23, 2026 · Langflow code Code Injection Remote Code Execution Vulnerability
60This week

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / package	Fixed version	Source
PyPI:langflow	1.7.1	Package registry (OSV)
PyPI:langflow-base	0.7.1	Package registry (OSV)

Exploit status

Proof of concept available

A public proof of concept or detection signature exists. Exploit knowledge is out there; don't delay patching.

Evidence

Nuclei detection template ×1
Proof-of-concept repository on GitHub ×1

Noroxi does not host or link to exploit code. Metasploit module names and Nuclei template ids are shown (names, not code); Exploit-DB entries and PoC repositories are given as counts only.

Public exploit evidence
Source	Kind	Date
Nuclei detection template	Nuclei template CVE-2026-21445	—
Proof-of-concept repository on GitHub	stars:1	2026-01-04

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

PublishedJan 2, 2026
First PoCJan 4, 2026+1 d
TodayNov 9, 2026+311 d

EPSS, last 120 days-1% in 7 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

langflow-ai/langflowcommit 3fed9fe

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

CVE-2025-3248270 days apartLangflow < 1.3.0 Unauthenticated RCE via /api/v1/validate/codeKEV
99Now
CVE-2026-9103196 days apartUnauthenticated Superuser Token Issuance via Auto-Login Endpoint
40Plan
CVE-2026-9202196 days apartUnauthenticated User Registration Could Lead to Remote Code Execution
39Monitor
CVE-2026-8505196 days apartAuthentication Bypass in Webhook Endpoints Allowed Unauthorized Flow Execution
39Monitor
CVE-2026-8446215 days apartLangflow is affected by security vulnerabilities in Model Context Protocol features
30Monitor
CVE-2026-19875229 days apartUnauthenticated Registration POST Endpoint Permits Admin Email Overwrite and Outbound Relay Abuse in Langflow
30Monitor

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

CVE-2025-6847814 days apartLangflow Vulnerable to External Control of File Name or Path
30Monitor
CVE-2026-077221 days apartLangflow Disk Cache Deserialization of Untrusted Data Remote Code Execution Vulnerability
30Monitor
CVE-2025-6847714 days apartLangflow vulnerable to Server-Side Request Forgery
28Monitor
CVE-2026-077121 days apartLangflow PythonFunction Code Injection Remote Code Execution Vulnerability
28Monitor

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

Anyone who can reach it over the internet can trigger it.
No account or password is required.
No user action is required.
No special conditions are required; it is repeatable.

If successful

Confidentiality
Integrity
Availability

Attack vector: Network
Attack complexity: Low
Privileges required: None
User interaction: None
Scope: X

Weakness class (CWE)

CWE-306 · Missing Authentication for Critical Function

CVSS vector

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

nvd-secondary

Root cause

A function added for development or support ships to production without authentication. It often relies on the assumption that it is “only reachable from the internal network.”

The bug in code

The whole CWE-306 class

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

1// Added for the support team
2app.post("/maintenance/reset", resetDevice);

Fixed

1if (config.maintenanceEnabled) {
2  app.post(
3    "/maintenance/reset",
4    requireSession, requireRole("admin"), resetDevice
5  );
6}

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

Attack patterns (CAPEC)

ATT&CK techniques

—

Change log

Fix✗ → ✓Sep 28, 2026, 10:46 PM UTC

For records you follow, these changes also arrive as notifications. →

References

github.com/langflow-ai/langflow/commit/3fed9fe1b5658f2c8656dbd73508e113a96e486a

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records

Noroxi analysis

What does it mean in your environment?

We use this product, ask for help

Data sources and verification

CNA: GitHub_M

CVE.org (CNA)Feb 26, 2026, 3:04 PM UTC
CISA ADPFeb 26, 2026, 3:04 PM UTC
NVDJun 17, 2026, 6:18 AM UTC
FIRST EPSSNov 8, 2026, 12:00 AM UTC
OSV / GHSANov 9, 2026, 3:18 AM UTC
NucleiNov 9, 2026, 3:18 AM UTC
PoC-in-GitHubNov 9, 2026, 3:18 AM UTC

Each line is when that source was last processed for this record.