CVE-2026-33309: Langflow is a tool for building and deploying AI-powered agents and workflows

This week

CRITICAL 9.9UPGRADE

CVE-2026-33309 is a critical-severity flaw (CVSS 9.9) affecting langflow. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Langflow is a tool for building and deploying AI-powered agents and workflows. Versions 1.2.0 through 1.8.1 have a bypass of the patch for CVE-2025-68478 (External Control of File Name), leading to the root architectural issue within `LocalStorageService` remaining unresolved. Because the underlying storage layer lacks boundary containment checks, the system relies entirely on the HTTP-layer `ValidatedFileName` dependency. This defense-in-depth f

Why this priority

Critical severity
EPSS top 4%: very likely to be exploited
Public exploit reference

A fixed release or distro patch exists.

Risk facts

CVSS score	9.9 (Critical)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	Low
User interaction	None
EPSS exploit chance	13.5% (top 4%)
CISA exploited list	No
Weakness	CWE-22, CWE-73, CWE-94, CWE-284
Published	2026-03-24
Last modified	2026-06-17

Publisher (CNA): GitHub, Inc. · Vendor: langflow

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-03-24 13:16 UTCPublished CVE record published
2026-06-17 10:37 UTCUpdated Record last modified

langflow langflow UPGRADE

Affected: >= 1.2.0 and < 1.9.0

Fixed in: 1.9.0

Safe to downgrade to: a release before 1.2.0

1. Check installed version

apt-cache policy langflow || rpm -q langflow || langflow --version

2. UPGRADE to 1.9.0 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade langflow

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade langflow

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

3. If no update is available yet, DOWNGRADE to a release before 1.2.0 (Debian / Ubuntu)

apt-cache madison langflow sudo apt install langflow=<VERSION_BEFORE_1.2.0> sudo apt-mark hold langflow

3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list langflow sudo dnf downgrade langflow-<VERSION_BEFORE_1.2.0> sudo dnf versionlock add langflow

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Exact fixes by distribution

Python (pip) · langflow · FIXED · 1.9.0 · vulnerable: >= 1.2.0, < 1.9.0 · source

pip install --upgrade "langflow>=1.9.0" pip show langflow

Fedora ELN · perl-Encode · FIXED · 3.25-528.eln159 · FEDORA-2026-79991d0238 · source

sudo dnf upgrade --advisory=FEDORA-2026-79991d0238

Fedora 46 · fonttools · FIXED · 4.68.0-1.fc46 · FEDORA-2026-65d6c01c75 · source

sudo dnf upgrade --advisory=FEDORA-2026-65d6c01c75

Public exploits and detection

Public code exists for this CVE. Treat unpatched systems as at risk, and only run PoCs in a lab.

Write-up: github.com/langflow-ai/langflow/security/advisories/GHSA-g2j9-7rj2-gm6c

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-33309?

langflow: upgrade to 1.9.0. Exact commands for each OS are on this page.

Is CVE-2026-33309 being exploited?

CVE-2026-33309 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-33309 affect?

CVE-2026-33309 affects langflow. Severity is critical (CVSS 9.9). Langflow is a tool for building and deploying AI-powered agents and workflows. Versions 1.2.0 through 1.8.1 have a bypass of the patch for CVE-2025-68478 (External Control of File Name), leading to the root architectural issue within `Local

How urgent is CVE-2026-33309?

Priority 64/100. Critical severity; EPSS top 4%: very likely to be exploited; Public exploit reference

Related CVEs

CVE-2026-34046 HIGH 8.8 UPGRADE UPGRADE Langflow is a tool for building and deploying AI-powered agents and workflows
CVE-2026-6542 MEDIUM 6.5 UPGRADE IBM Langflow OSS 1.0.0 through 1.8.4 could allow any user to supply a flow_id to read transaction logs and ver
CVE-2026-7524 CRITICAL 9.8 UPGRADE IBM Langflow OSS 1.0.0 through 1.9.1 could allow remote code execution due to improper validation of symbolic
CVE-2026-48519 CRITICAL 9.6 UPGRADE Langflow is a tool for building and deploying AI-powered agents and workflows
CVE-2026-33760 HIGH 8.8 UPGRADE Langflow is a tool for building and deploying AI-powered agents and workflows

References

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