CVE-2026-10561: Langflow: PythonREPLComponent executes unsandboxed Python code, enabling authenticated RCE and privilege escalation

Should you act?

Critical and remotely reachable

No known exploitation yet, but it is network-reachable without credentials. This signal is computed from CISA KEV, EPSS and CVSS data; it is not an editorial verdict.

• No confirmed exploitation. It is not in CISA’s KEV catalog and CISA’s SSVC assessment records no known exploitation. That can change quickly after a public write-up; re-check if you are affected.
• EPSS 0.8%, percentile 57: FIRST’s model estimates a 0.8% chance of exploitation activity in the next 30 days, higher than 57% of all scored CVEs (moderate). EPSS is a probability, not a verdict.
• Remotely reachable with no login and no user interaction. If the vulnerable service is exposed to the internet, prioritize it.
• Only applies if your dependency tree includes langflow (PyPI) < 1.10.1, fixed in 1.10.1. Check your lockfile, including transitive dependencies.

What it is

IBM Langflow OSS 1.0.0 through 1.9.3 has an vulnerability due to an improper isolation of Python execution combined with an authentication bypass that allows an unauthenticated attacker to execute arbitrary code on the host system, resulting in complete compromise

From the GitHub advisory

Summary

Langflow's built-in Python interpreter components — PythonREPLComponent (Python Interpreter) and the legacy PythonREPLToolComponent (Python REPL Tool) — executed arbitrary user- or model-supplied Python code inside flows without effective sandboxing. Because the code ran in-process with the privileges of the Langflow service, any authenticated user who could edit and run a flow could achieve remote code execution and, from there, escalate privileges to superuser (e.g. by opening a database session and flipping issuperuser) or compromise the host.

This issue is fixed as of 1.10.1, with additional hardening through 1.12.3. See Remediation below.

Affected

- Package: langflow (PyPI), and the underlying lfx package that ships the component. - Vulnerable versions: = 1.12.3 for the complete hardening series.

Weakness type: CWE-94, CWE-95, CWE-266.

Product: langflow (PyPI) · Assigned by: ibm · Published: 2026-06-22

Affected and fixed versions

Severity scores

• Attack vector: network (remotely reachable)
• Attack complexity: low
• Privileges required: none (no login)
• User interaction: none
• Scope: changed (can affect other components)

CVSS measures how bad a flaw is if exploited, not how likely exploitation is. Read it next to the exploitation data below.

Exploitation and urgency

• CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
• CISA SSVC assessment: exploitation none, automatable yes, technical impact total.
• FIRST EPSS (model of 2026-10-21): 0.82% probability of exploitation activity in the next 30 days; percentile 57.

Timeline

• 2026-06-22 — CVE record published by ibm
• 2026-06-23 — CVE record last updated
• 2026-10-06 — GitHub-reviewed advisory GHSA-8qpj-27x8-pwpq published (critical)

Sources and references

Original sources first. Version and fix details should always be confirmed against the vendor or project advisory.

Vendor and project advisories, patches

1. ibm.com ibm.com

Vulnerability records

1. GitHub Advisory GHSA-8qpj-27x8-pwpq github.com
2. CVE.org record CVE-2026-10561 cve.org
3. NVD entry CVE-2026-10561 nvd.nist.gov

Other references from the CVE record and advisory

1. github.com github.com
2. github.com github.com
3. github.com github.com
4. github.com github.com

Critical PyPI advisories · Today’s Security Digest