CVE-2026-9138: IBM Langflow OSS 1.0.0 through 1.11.2 Langflow could allow an authenticated attacker to write arbitrary files

Routine

MEDIUM 6.5UPGRADE

CVE-2026-9138 is a medium-severity flaw (CVSS 6.5) 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 1.11.2 Langflow could allow an authenticated attacker to write arbitrary files to the server due to improper input validation in the SaveToFileComponent. The application constructs local file paths using attacker‑controlled input without sufficient sanitization when handling requests to the /api/v1/run/{flow_id} endpoint. An attacker with low‑privileged authenticated access (such as a valid API key or user session)

Why this priority

No elevated risk signals yet

A fixed release or distro patch exists.

Risk facts

CVSS score	6.5 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	Low
User interaction	None
EPSS exploit chance	0.5% (top 61%)
CISA exploited list	No
Weakness	CWE-22
Published	2026-09-04
Last modified	2026-09-10

Publisher (CNA): IBM Corporation · Vendor: langflow

Last updated 2026-09-10 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-09-04 15:17 UTCPublished CVE record published
2026-09-10 21:17 UTCUpdated Record last modified

langflow langflow UPGRADE

Affected: >= 1.0.0 and < 1.11.3

Fixed in: 1.11.3

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 1.11.3 (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-2026-9138?

langflow: upgrade to 1.11.3. Exact commands for each OS are on this page.

Is CVE-2026-9138 being exploited?

CVE-2026-9138 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-2026-9138 affect?

CVE-2026-9138 affects langflow. Severity is medium (CVSS 6.5). IBM Langflow OSS 1.0.0 through 1.11.2 Langflow could allow an authenticated attacker to write arbitrary files to the server due to improper input validation in the SaveToFileComponent. The application constructs local file paths using attac

How urgent is CVE-2026-9138?

Priority 32/100. No elevated risk signals yet.

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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