CVE-2026-7664: IBM Langflow OSS 1.0.0 through 1.8.4 could allow unauthenticated attackers to access protected MCP project res

This month

CRITICAL 9.8REMOTEUPGRADE

CVE-2026-7664 is a critical-severity flaw (CVSS 9.8) affecting langflow. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

IBM Langflow OSS 1.0.0 through 1.8.4 could allow unauthenticated attackers to access protected MCP project resources and execute MCP operations due to improper authorization enforcement in the Streamable MCP transport endpoint.

Why this priority

Critical severity
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	9.8 (Critical)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.5% (top 58%)
CISA exploited list	No
Weakness	CWE-287
Published	2026-06-22
Last modified	2026-10-25

Publisher (CNA): IBM Corporation · Vendor: langflow

Last updated 2026-10-25 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-06-22 16:16 UTCPublished CVE record published
2026-10-25 23:10 UTCUpdated Record last modified

langflow langflow UPGRADE

Affected: >= 1.0.0 and <= 1.8.4

Fixed in: newer than 1.8.4

Safe to downgrade to: a release before 1.0.0

1. Check installed version

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

2. UPGRADE to newer than 1.8.4 (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 1.0.0 (Debian / Ubuntu)

apt-cache madison langflow sudo apt install langflow=<VERSION_BEFORE_1.0.0> 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_1.0.0> 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.

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-2026-7664?

langflow: upgrade to newer than 1.8.4. Exact commands for each OS are on this page.

Is CVE-2026-7664 being exploited?

CVE-2026-7664 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-2026-7664 affect?

CVE-2026-7664 affects langflow. Severity is critical (CVSS 9.8). IBM Langflow OSS 1.0.0 through 1.8.4 could allow unauthenticated attackers to access protected MCP project resources and execute MCP operations due to improper authorization enforcement in the Streamable MCP transport endpoint.

How urgent is CVE-2026-7664?

Priority 50/100. Critical severity; Remotely exploitable, no login, no user action

Related CVEs

CVE-2026-7528 HIGH 7.1 UPGRADE IBM Langflow OSS 1.0.0 through 1.9.0 could allow a denial of service due to uncontrolled resource consumption.
CVE-2026-5022 MEDIUM 5.3 MITIGATE The '/api/v1/files/images/{flow_id}/{file_name}' endpoint does not enforce any authentication or authorization
CVE-2026-55255 HIGH 8.4 EXPLOITED UPGRADE Langflow Authorization Bypass Through User-Controlled Key Vulnerability
CVE-2026-55450 CRITICAL 9.3 UPGRADE Langflow is a tool for building and deploying AI-powered agents and workflows
CVE-2026-10561 CRITICAL 10.0 UPGRADE IBM Langflow OSS 1.0.0 through 1.9.3 has an vulnerability due to an improper isolation of Python execution com

References

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