# CVE-2025-3248: Langflow Missing Authentication Vulnerability

- Exploited (CISA KEV): yes, added 2025-05-05, known ransomware use
- Published: 2025-04-07
- CVSS: 9.8 CRITICAL (v3.1)
- EPSS: 100.0% (100th percentile)
- CWE: CWE-306

Langflow versions prior to 1.3.0 are susceptible to code injection in 
the /api/v1/validate/code endpoint. A remote and unauthenticated attacker can send crafted HTTP requests to execute arbitrary
code.

## Edge WAF coverage (claimed by vendors, not measured)

| Vendor | Status | First rule | Days after publication |
|---|---|---|---|
| Cloudflare | Blocks by default | 2025-05-05 | 28 |
| AWS | No public claim | — | — |
| Microsoft Azure | No public claim | — | — |
| Google Cloud | No public claim | — | — |
| Fastly | Before feed history | — | — |
| F5 | Rule published | 2025-06-30 | 84 |
| Akamai | No public source | — | — |
| OWASP CRS | No public claim | — | — |

### Cloudflare

- 2025-05-05 · new · rule 1a11fbe84b49451193ee1ee6d29da333 · default Block
  > Langflow - Remote Code Execution - CVE:CVE-2025-3248. Previous action: Log. New action: Block. This is a New Detection
  Source: https://developers.cloudflare.com/changelog/post/2025-05-05-waf-release/

### F5

- 2025-06-30 · new · rule 200204017
  > Added: signature 200204017 "Langflow Code Injection" (Server Side Code Injection, risk High), systems: Python. References: CVE-2025-3248.
  Source: https://docs.cloud.f5.com/docs-v2/platform/changelogs/security-details-changelog
- 2026-09-16 · updated · rule 200204017
  > Updated: signature 200204017 "Langflow Code Injection" (Server Side Code Injection, risk High), systems: Python. References: CVE-2025-3248, CVE-2026-9198, CVE-2026-0768.
  Source: https://docs.cloud.f5.com/docs-v2/platform/changelogs/security-details-changelog
- 2026-10-21 · updated · rule 200204017
  > Updated: signature 200204017 "Langflow Code Injection" (Server Side Code Injection, risk High), systems: Python. References: CVE-2025-3248, CVE-2026-9198, CVE-2026-0768, CVE-2026-93674.
  Source: https://docs.cloud.f5.com/docs-v2/platform/changelogs/security-details-changelog

## Our test (measured)

- OWASP Core Rule Set 4.25.0, paranoia level 1, anomaly threshold 5, default CRS settings: blocked (1 of 1 requests blocked), template CVE-2025-3248, 2026-11-02
- OWASP Core Rule Set 4.25.0, paranoia level 2, anomaly threshold 5, default CRS settings: blocked (1 of 1 requests blocked), template CVE-2025-3248, 2026-11-02

"No public claim" means no vendor statement names this CVE; "Before feed history" means the CVE is older than the vendor feed. In both cases generic rules may still block it.

HTML: https://cve.vigilbase.com/cve/CVE-2025-3248 · JSON: https://cve.vigilbase.com/api/v1/cves/CVE-2025-3248