Langflow unauthenticated code injection in validate/code endpoint
Langflow < 1.3.0: unauthenticated code injection allows RCE via crafted HTTP requests to /api/v1/validate/code. CVSS 9.8 critical. CISA KEV 2025-05-05.
- Vendor
- Langflow
- Product
- Langflow
- CVSS
- 9.8
- EPSS (exploit probability)
- 100.0%
- Status
- kevransomware use
- CISA patch-by (BOD 22-01)
- Published
Is CVE-2025-3248 being exploited?
Yes. CISA added CVE-2025-3248 to its Known Exploited Vulnerabilities catalog on . CISA only lists a CVE when it has reliable evidence of exploitation in the wild. CISA marks it as known to be used in ransomware campaigns.
FIRST's EPSS model puts the probability of exploitation activity in the next 30 days at 100.0% (scored October 14, 2026).
- CISA KEV[ LISTED ]
- ENISA EUVD (exploited)[ — ]
- CIRCL KEV[ — ]
Catalog snapshot 2026-10-22. Full cross-catalog view: /kev-comparison
What to do
US federal civilian agencies must remediate by (21 days after listing) under BOD 22-01. Everyone else: that deadline is a sensible upper bound, not a target. Vendor guidance and the NVD record are linked under Source above.
Langflow versions prior to 1.3.0 contain a code injection vulnerability in the /api/v1/validate/code endpoint. A remote, unauthenticated attacker can send crafted HTTP requests to execute arbitrary code on the server. No credentials required, no user interaction required.
CISA added CVE-2025-3248 to the Known Exploited Vulnerabilities catalog on 2025-05-05, confirming active exploitation in the wild. Source: NVD.
Affected versions
Langflow versions prior to 1.3.0.
What to do
Upgrade to Langflow 1.3.0 or later. Given Langflow’s history of repeated critical RCE vulnerabilities in the same platform — this is the first of five KEV entries in fourteen months — upgrading to the current 1.9.x release rather than stopping at 1.3.0 is the correct posture. Each interim KEV entry (CVE-2026-33017, CVE-2025-34291, CVE-2026-55255, CVE-2026-0770) represents an additional unpatched path if you stop short of current.
Any instance reachable from the internet on a version below 1.3.0 should be treated as likely compromised and investigated before relying on it.
Other Langflow CVEs we track
| CVE / Vulnerability | Severity | CVSS | EPSS | Added to KEV |
|---|---|---|---|---|
| CVE-2026-105740 Authenticated RCE via MCP tool additionwrite-up | [ CRITICAL ] | 9.9 | 0.6% | — |
| CVE-2026-0768 Langflow Unauthenticated RCE via Code Execution Endpointwrite-up | [ CRITICAL ] | 9.8 | 22.9% | — |
| CVE-2026-0770 Langflow validate-endpoint exec_globals RCE (unauthenticated)write-up | [ CRITICAL ] | 9.8 | 62.6% | |
| CVE-2026-55255 Langflow /api/v1/responses IDOR — cross-user flow executionwrite-up | [ HIGH ] | 8.4 | 0.9% | |
| CVE-2025-34291 Langflow CORS misconfiguration enables CSRF-driven token theft and RCEwrite-up | [ HIGH ] | 8.8 | 92.8% | |
| CVE-2026-33017 Langflow public flow build endpoint allows unauthenticated RCEwrite-up | [ CRITICAL ] | 9.8 | 24.8% |
