Vulnerability record · CVE-2026-33873 · published 27 March 2026

CVE-2026-33873: Langflow code injection vulnerability

Langflow · Langflow

Langflow is a tool for building and deploying AI-powered agents and workflows. Prior to version 1.9.0, 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. Version 1.9.0 fixes the issue.

9.3 CVSS 4.0 Critical EPSS 1.8% · top 22.2% CWE-94 · Code injection

9.3CVSS 4.0 base score

1.8%EPSS exploitation probability, 30 days

NoNot in CISA KEV

1Affected product versions listed by NVD

16References, 1 tagged exploit

17 Jun 2026Last modified by NVD

Description

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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:

Affected products

1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

Langflow Langflow

References

Link	Tags
https://github.com/langflow-ai/langflow/blob/f7f4d1e70ba5eecd18162ec96f3571c2cfbcd1fc/src/backend/base/langflow/agentic/	Product
https://github.com/langflow-ai/langflow/blob/f7f4d1e70ba5eecd18162ec96f3571c2cfbcd1fc/src/backend/base/langflow/agentic/	Product
https://github.com/langflow-ai/langflow/blob/f7f4d1e70ba5eecd18162ec96f3571c2cfbcd1fc/src/backend/base/langflow/agentic/	Product
https://github.com/langflow-ai/langflow/blob/f7f4d1e70ba5eecd18162ec96f3571c2cfbcd1fc/src/backend/base/langflow/agentic/	Product
https://github.com/langflow-ai/langflow/blob/f7f4d1e70ba5eecd18162ec96f3571c2cfbcd1fc/src/backend/base/langflow/agentic/	Product
https://github.com/langflow-ai/langflow/blob/f7f4d1e70ba5eecd18162ec96f3571c2cfbcd1fc/src/backend/base/langflow/agentic/	Product
https://github.com/langflow-ai/langflow/blob/f7f4d1e70ba5eecd18162ec96f3571c2cfbcd1fc/src/backend/base/langflow/agentic/	Product
https://github.com/langflow-ai/langflow/blob/f7f4d1e70ba5eecd18162ec96f3571c2cfbcd1fc/src/backend/base/langflow/api/util	Product
https://github.com/langflow-ai/langflow/blob/f7f4d1e70ba5eecd18162ec96f3571c2cfbcd1fc/src/backend/base/langflow/api/v1/l	Product
https://github.com/langflow-ai/langflow/blob/f7f4d1e70ba5eecd18162ec96f3571c2cfbcd1fc/src/backend/base/langflow/services	Product
https://github.com/langflow-ai/langflow/blob/f7f4d1e70ba5eecd18162ec96f3571c2cfbcd1fc/src/backend/base/langflow/services	Product
https://github.com/langflow-ai/langflow/blob/f7f4d1e70ba5eecd18162ec96f3571c2cfbcd1fc/src/lfx/src/lfx/custom/validate.py	Product
https://github.com/langflow-ai/langflow/blob/f7f4d1e70ba5eecd18162ec96f3571c2cfbcd1fc/src/lfx/src/lfx/custom/validate.py	Product
https://github.com/langflow-ai/langflow/blob/f7f4d1e70ba5eecd18162ec96f3571c2cfbcd1fc/src/lfx/src/lfx/custom/validate.py	Product
https://github.com/langflow-ai/langflow/blob/f7f4d1e70ba5eecd18162ec96f3571c2cfbcd1fc/src/lfx/src/lfx/services/settings/	Product
https://github.com/langflow-ai/langflow/security/advisories/GHSA-v8hw-mh8c-jxfc	ExploitMitigationVendor Advisory

Track CVE-2026-33873 inside VULONE

Watch it alongside the ransomware crews, C2 infrastructure and forum chatter that reference it, query it through the API and pull it into your SIEM over TAXII.

Start free Open in platform

Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

9.8CVE-2026-9198Langflow auto_login and code validation chain enables unauthenticated RCEIBM Langflow OSS 1.0.0 through 1.10.0 exposes /api/v1/auto_login, which mints SUPERUSER tokens to any network caller, and /api/v1/validate/code, whic…KEVEPSS 29%analysed17 Jul 2026 9.8CVE-2026-0770Langflow validate endpoint exec_globals remote code executionLangflow mishandles the exec_globals parameter passed to its validate endpoint, allowing functionality from an untrusted control sphere to be include…KEVEPSS 64%analysed23 Jan 2026 9.8CVE-2025-3248Langflow unauthenticated code injection in validate/code endpointLangflow versions prior to 1.3.0 expose the /api/v1/validate/code endpoint without authentication, allowing code injection. A remote attacker can sen…KEVEPSS 100%analysed7 Apr 2025 9.4CVE-2025-34291Langflow CORS misconfiguration leads to token theft and RCELangflow up to and including 1.6.9 ships an overly permissive CORS configuration (allow_origins='*' with allow_credentials=True) and a refresh token …KEVEPSS 93%analysed5 Dec 2025 9.3CVE-2026-33017Langflow build_public_tmp endpoint unauthenticated remote code executionLangflow versions prior to 1.9.0 expose the POST /api/v1/build_public_tmp/{flow_id}/flow endpoint without authentication, and when the optional data …KEVEPSS 25%analysed20 Mar 2026 8.4CVE-2026-55255Langflow IDOR in responses endpoint allows cross-user flow executionLangflow before 1.9.1 has an insecure direct object reference in the /api/v1/responses endpoint. An authenticated attacker can supply another user's …KEVEPSS 0.89%analysed23 Jun 2026 10.0CVE-2026-10134Langflow code injection vulnerabilityIBM Langflow OSS 1.0.0 through 1.9.3 allows an attacker to read every secret available to the Langflow process, read and modify every flow, conversat…EPSS 0.64%30 Jun 2026 10.0CVE-2026-10561Langflow code injection vulnerabilityIBM 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 tha…EPSS 1.0%22 Jun 2026

Source: NIST National Vulnerability Database (record CVE-2026-33873), CISA KEV, FIRST EPSS (scores of 2026-09-26). This page is refreshed as NVD updates the record.