CVE-2026-33017: Langflow Code Injection Vulnerability
- Is it exploited?
Yes. CISA added it to the Known Exploited Vulnerabilities catalog on 25 Mar 2026, 5 days after the CVE record was published.
- How likely is exploitation in the next 30 days?
- 96.2%
EPSS score, percentile 99.9 of all scored records
- How severe?
- 9.3 Critical
CVSS v4.0 base score, given by the CNA
- What should I do?
Required action (CISA), due 8 Apr 2026: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
The CVE record links no vendor advisory, patch or mitigation.
- Which versions are affected?
Affected: < 1.9.0
Source: CISA Known Exploited Vulnerabilities (KEV) catalog, 2026.10.28, as of 28 Oct 2026; FIRST Exploit Prediction Scoring System (EPSS), v2026.06.15, as of 28 Oct 2026; CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of 28 Oct 2026. About the data.
What to do
Required action, set by CISA
Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
CISA due date for this action: 8 April 2026.
Advisories and patches
The CVE record links no vendor advisory, patch or mitigation.
Linked from CISA's catalog entry
- https://github.com/langflow-ai/langflow/security/advisories/GHSA-vwmf-pq79-vjvx
- https://nvd.nist.gov/vuln/detail/CVE-2026-33017
Affected products and versions
As listed in the CVE record.
| Status | Versions |
|---|---|
| Affected | < 1.9.0 |
Source: CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of 28 Oct 2026. About the data.
About this vulnerability
Langflow contains a code injection vulnerability that could allow building public flows without requiring authentication.
Summary: CISA's KEV catalog, as of 28 Oct 2026.
- CISA added CVE-2026-33017 to its Known Exploited Vulnerabilities (KEV) catalog on 25 Mar 2026.
- CISA's ransomware flag for this entry is "Unknown": no evidence of ransomware use in the catalog, which is not proof of none.
- The due date CISA sets for the required action is 8 Apr 2026.
- The CVE record was published on 20 Mar 2026, 5 days before it was added to KEV.
- The CVE record carries a CVSS v4.0 base score of 9.3 (Critical), given by its CNA.
- FIRST's EPSS model puts the probability of exploitation in the next 30 days at 96.2% (percentile 99.9), as of 28 Oct 2026.
- CISA's SSVC assessment in the CVE record: exploitation active, automatable yes, technical impact total.
Source: CISA Known Exploited Vulnerabilities (KEV) catalog, 2026.10.28, as of 28 Oct 2026; CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of 28 Oct 2026; FIRST Exploit Prediction Scoring System (EPSS), v2026.06.15, as of 28 Oct 2026. About the data.
Description
Langflow has Unauthenticated Remote Code Execution via Public Flow Build Endpoint
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.
Source: CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of 28 Oct 2026. About the data.
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
CWE and CAPEC are maintained by MITRE; the entries are those named in the CVE record and the KEV entry.
Timeline
| Date | Event |
|---|---|
| 20 Mar 2026 | CVE record published |
| 25 Mar 2026 | Added to CISA KEV |
| 8 Apr 2026 | CISA due date for the required action |
| 21 May 2026 | CVE record last updated |
References
- https://github.com/langflow-ai/langflow/security/advisories/GHSA-vwmf-pq79-vjvx
- https://github.com/langflow-ai/langflow/commit/73b6612e3ef25fdae0a752d75b0fabd47328d4f0
- https://github.com/advisories/GHSA-rvqx-wpfh-mfx7
More exploited Langflow vulnerabilities
- CVE-2026-0770: Langflow Inclusion of Functionality from Untrusted Control Sphere Vulnerability
- CVE-2026-55255: Langflow Authorization Bypass Through User-Controlled Key Vulnerability
- CVE-2025-34291: Langflow Origin Validation Error Vulnerability
- CVE-2025-3248: Langflow Missing Authentication Vulnerability