CVE-2026-33017 — Langflow Vulnerability

What is CVE-2026-33017?

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.

The record classifies CVE-2026-33017 under weakness classes CWE-94, CWE-95, CWE-306. Its CVSS v3 base vector states that the flaw is reachable remotely over the network, needs no prior authentication, needs no user interaction, and has high impact on confidentiality, integrity, availability. 1 affected-product entry is recorded, across 1 vendor, listed below. The identifier was first published 222 days ago.

Severity and exploitation probability

CVSS v3.1 base score: 9.8 — CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CVSS v4.0 base score: 9.3
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
EPSS (FIRST): 24.7% probability of exploitation in the next 30 days, higher than 97.8% of all scored CVEs
CISA KEV: Listed since 2026-03-25, federal remediation deadline 2026-04-08
Threadlinqs priority: 9/10 — CISA KEV-listed, which Threadlinqs floors at 9
Published: 2026-03-20, last modified 2026-05-21

Is CVE-2026-33017 being exploited?

CISA added CVE-2026-33017 to the Known Exploited Vulnerabilities catalog on 2026-03-25, which means the agency holds evidence of exploitation in the wild; US federal civilian agencies had to remediate it by 2026-04-08 under BOD 22-01. Weaponised exploit code for CVE-2026-33017 is publicly available. 11 public proof-of-concept repositories are tracked for this identifier. A ProjectDiscovery Nuclei detection template exists (http/cves/2026/CVE-2026-33017.yaml). It currently carries a trending score of 49 in the Threadlinqs vulnerability feed.

EQSTLab/CVE-2026-33017 (github)
MaxMnMl/langflow-CVE-2026-33017-poc (github)
z4yd3/PoC-CVE-2026-33017 (github)
c0gnit00/CVE-2026-33017 (github)
CerberusMrXi/Langflow-cve-2026-33017-exploit (github)
omer-efe-curkus/CVE-2026-33017-Langflow-RCE-PoC (github)
Jorrit-VM/CVE-2026-33017 (github)
Industri4l-H3ll-Xpl0it3rs/CVE-2026-33017-Langflow-RCE (github)

Affected products and versions

Langflow: Langflow

How to fix CVE-2026-33017

The record marks a vendor fix as available for CVE-2026-33017. Patch reference: https://github.com/langflow-ai/langflow/commit/73b6612e3ef25fdae0a752d75b0fabd47328d4f0. Vendor advisory: https://github.com/langflow-ai/langflow/commit/73b6612e3ef25fdae0a752d75b0fabd47328d4f0. Because CVE-2026-33017 is KEV-listed, US federal civilian agencies were required to apply the vendor fix, or stop using the product, by 2026-04-08. Apply the vendor fix referenced above to every affected product listed in this record, then confirm the running version against the vendor advisory.

Threat activity tracking CVE-2026-33017

7 tracked threats in the Threadlinqs corpus reference CVE-2026-33017, either in the campaign’s CVE list or as an indicator on the campaign record.

CVE-2026-34486: Apache Tomcat EncryptInterceptor Bypass Actively Exploited in SnowLight and AI-Assisted Campaigns — HIGH · 2026-08-05
JADEPUFFER: AI Agent Exploits Langflow RCE (CVE-2025-3248) to Automate Database Ransomware/Extortion Attack — CRITICAL · 2026-07-05
JADEPUFFER: First End-to-End Agentic Ransomware Attack Exploiting Langflow (CVE-2025-3248) and Nacos (CVE-2021-29441) — CRITICAL · 2026-07-02
Langflow CVE-2026-33017 Unauthenticated RCE Actively Exploited for Monero Mining (lambsys) — CRITICAL · 2026-06-30
NATS-as-C2: KeyHunter Distributed Worker Botnet Harvests Cloud Credentials and AI API Keys via Langflow RCE (CVE-2026-33017) — HIGH · 2026-05-14
CVE-2026-44338 PraisonAI Unauthenticated API Bypass — Active Exploitation Within 4 Hours of Disclosure (Sysdig TRT) — HIGH · 2026-05-12
CVE-2026-33017: Langflow Unauthenticated RCE via Public Flow Build Endpoint — Active Exploitation Within 20 Hours — CRITICAL · 2026-03-19

Sources

Enriched from CVE.org, NVD, FIRST EPSS, CISA KEV, public proof-of-concept repositories, ProjectDiscovery Nuclei. Last verified by Threadlinqs on 2026-10-10. This product uses the NVD API but is not endorsed or certified by the NVD.

Vendor advisory and patch

github.com

Other references

Showing 6 of 8 recorded references.