How severe is CVE-2026-21445?

No CVSS score has been assigned to CVE-2026-21445 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by CVE-2026-21445?

CVE-2026-21445 affects the following packages: langflow-base (PyPI), langflow (PyPI). Ecosystems affected: PyPI.

How do I fix CVE-2026-21445?

Update langflow-base to 0.7.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-21445 is resolved across your whole dependency graph.

How do I detect CVE-2026-21445 in my PyPI dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for langflow-base, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2026-21445 if there is no patch (or I can't update yet)?

If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

How does O3 Security protect against CVE-2026-21445?

O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2026-21445 can be triaged on real exposure rather than presence alone.

Is CVE-2026-21445 actively exploited in the wild?

No public exploit code has been indexed for CVE-2026-21445 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2026-21445?

CVE-2026-21445 has an EPSS (Exploit Prediction Scoring System) score of 33.7%, placing it in the 98th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score warrants monitoring and prompt remediation.

What type of vulnerability is CVE-2026-21445?

CVE-2026-21445 is classified as Missing Authentication (CWE-306). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

Is there exploit tooling available for CVE-2026-21445?

A Nuclei detection template exists for CVE-2026-21445, meaning automated scanners can fingerprint it. Public exploit tooling significantly increases real-world risk — prioritize patching and ensure detection coverage. Exploit tooling should only ever be used in isolated, authorized testing environments.

When was CVE-2026-21445 published, and has it been updated?

CVE-2026-21445 was published on January 2, 2026 and was last updated on August 12, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🐍 PyPI

Not in CISA KEV

CVE-2026-21445 — langflow-base

Fix: langflow-ai/langflow@3fed9fe

CVE-2026-21445 is a Missing Authentication vulnerability in langflow-base. EPSS puts its 30-day exploitation probability at 33.7% (98th percentile). A fix is available for langflow-base — see the affected versions and patch details below.

Langflow Missing Authentication on Critical API Endpoints

Also known asGHSA-c5cp-vx83-jhqxPYSEC-2026-1524PYSEC-2026-2571

Published

Jan 2, 2026

Updated

Aug 12, 2026

Affected

2 pkgs

Patched

2 / 2

Exploits

None indexed

Exploitation data as of Sep 20, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
A successful exploit gives an attacker total control of the affected component, not partial access.
CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for CVE-2026-21445.

EPSS Exploitation Probability

via FIRST.org ↗

33.7%probability of exploitation in next 30 days

Moderate Risk0.00%

Lower risk than most CVEs98th percentile — riskier than 98% of all scored CVEsHighest risk

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

Real-World Exposure

2 pkgs affected

🐍langflow-base🐍langflow

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.

Description

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.

Affected Packages

2 total 2 fixed

Ecosystem	Package	Vulnerable range	Fix
🐍PyPI	`langflow-base`	all versions	0.7.1`pip install --upgrade 'langflow-base==0.7.1'`
🐍PyPI	`langflow`	all versions	1.7.1`pip install --upgrade 'langflow==1.7.1'`

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for langflow-base, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update langflow-base to 0.7.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-21445 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2026-21445 can be triaged on real exposure rather than presence alone.

Tailored to CVE-2026-21445. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

How to detect CVE-2026-21445

A community-maintained Nuclei template exists for this CVE. You can scan for it directly:

nuclei -id cve-2026-21445 -u https://target

Template: Langflow - Broken Access Control
Severity: critical
Impact: Unauthenticated attackers can access sensitive user data and perform destructive actions, risking data loss and privacy breaches.
Remediation: Update to version 1.7.0.dev45 or later.

Template by ProjectDiscovery nuclei-templates (DhiyaneshDk), MIT licensed. View the full template. Scan only systems you are authorised to test.

Frequently Asked Questions

O3 Security · Impact-Aware SCA

Is CVE-2026-21445 in your dependencies?

O3 Security finds CVE-2026-21445 across PyPI dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.

Scan my dependencies How O3 SCA works