Langflow has Authenticated Code Execution in Agentic Assistant Validation

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS 4.0

9.3 · CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:N/SC:H/SI:H/SA:N · score source

EPSS

• CVE-2026-33873: 1.45% estimated exploitation activity in the next 30 days; percentile 73.42 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Description 1. Summary The Agentic Assistant feature in Langflow executes LLM-generated Python code during its validation phase. Although this phase appears intended to validate generated component code, the implementation reaches dynamic execution sinks and instantiates the generated class server-side. In deployments where an attacker can access the Agentic Assistant feature and influence the model output, this can result in arbitrary server-side Python execution. 2. Description 2.1 Intended Functionality The Agentic Assistant endpoints are designed to help users generate and validate components for a flow. Users can submit requests to the assistant, which returns candidate component code for further processing. A reasonable security expectation is that validation should treat model output as untrusted text and perform only static or side-effect-free checks. The externally reachable endpoints are:…

Published by the source

26 Mar 2026, 18:31 UTC

Last modified by the source

6 Jun 2026, 01:00 UTC

Source last checked

26 Oct 2026, 13:44 UTC

1. Revision 4 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-v8hw-mh8c-jxfc

2. Revision 3 · amended · 25 Oct 2026

   Reviewed OSV alias/range/CVSS4 correction; package source scopes and original publication preserved. No customer finding resolved.

3. Revision 2 · amended · 24 Oct 2026

   Amended from osv record GHSA-v8hw-mh8c-jxfc

4. Revision 1 · created · 23 Oct 2026

   Published from ghsa record GHSA-v8hw-mh8c-jxfc

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# Patch Next advisory brief: CVE-2026-33873

Advisory: Langflow has Authenticated Code Execution in Agentic Assistant Validation
IDs: CVE-2026-33873, GHSA-v8hw-mh8c-jxfc
Record: https://patchnext.com/advisories/cve-2026-33873 (revision 4, source checked 26 Oct 2026, 13:44 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Critical (CVSS 9.3)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: langflow 1.9.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- PyPI langflow: affected <= 1.8.1; fixed in 1.9.0

## Suggested inspection (read-only)
- `python -m pip show langflow`: prints the installed version. Run with the environment that serves production active.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on langflow.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-v8hw-mh8c-jxfc (GitHub-reviewed advisory GHSA-v8hw-mh8c-jxfc lists affected ranges: PyPI langflow >=0 <=1.8.1)
- Verified: https://osv.dev/vulnerability/GHSA-v8hw-mh8c-jxfc (OSV record GHSA-v8hw-mh8c-jxfc lists affected ranges: PyPI langflow >=0 <1.9.0 (fixed))

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