Langflow Code Injection Vulnerability
Exploited since 2026-03-25. 1 of 8 rule sources name it. Our CRS test: partly blocked.
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… More
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.
Edge coverage
Claimed by vendorsAsk Vigil
AI · answers from this pageWorkers AI (Llama 3.3). Can be wrong: check the cited source.
Severity, decoded
CVSS 4.0Exploitable over the network, with no privileges and no user interaction, leading to full loss of confidentiality, integrity and availability; other systems can also be hit (low impact on confidentiality, integrity and availability).
How the score is built
- Attack vectorAn attacker can reach it over the internet; no access to your network needed.Network
- Attack complexityNo built-in defences have to be bypassed; the attack works reliably.Low
- Attack requirementsThe attack works without any special deployment or timing conditions.None
- Privileges requiredNo account or login is needed.None
- User interactionNo one has to click or open anything; the attack works on its own.None
- Confidentiality impact (vulnerable system)An attacker can read all data the affected component holds, or the most sensitive parts of it.High
- Integrity impact (vulnerable system)An attacker can change any data or files the affected component protects.High
- Availability impact (vulnerable system)An attacker can take the component down completely or keep it from serving anyone.High
- Confidentiality impact (other systems)Other systems that rely on it can have some data read.Low
- Integrity impact (other systems)Other systems that rely on it can have some data changed.Low
- Availability impact (other systems)Other systems that rely on it can be slowed down or interrupted.Low
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:L/SI:L/SA:LAttackers are exploiting this in the wild.
Attackers can script the attack end to end and hit many targets at once.
A successful attack gives full control over the affected software or all of its data.
Public exploits
3 found- MetasploitLangflow Unauth RCE2026-03-20 · exploit · rank Excellent · has check
- Exploit-DBLangflow 1.9.0 - RCE2026-07-08 · webapps · multiple
- NucleiCVE-2026-33017.yamldetection template, replayed in our lab
Links are to third-party code: never run it outside an isolated lab.
Timeline
- 2026-03-20CVE publishedCVE List
- 2026-03-20Metasploit module publishedLangflow Unauth RCE
- 2026-03-25Added to CISA KEVConfirmed exploitation in the wild
- 2026-07-07F5 ships a ruleLangflow Code Injection (2)
- 2026-07-08Exploit published on Exploit-DBLangflow 1.9.0 - RCE
- 2026-11-02Our test: OWASP Core Rule Set blocked part of itparanoia level 1, anomaly threshold 5, default CRS settings
- 2026-11-02Our test: OWASP Core Rule Set blocked part of itparanoia level 2, anomaly threshold 5, default CRS settings
Vendor statements
QuotedCloudflareWAF Managed Rules
We found no public statement from this vendor naming this CVE. That is not proof of no protection: generic rules may still catch it. Each row gives the rule ID and its default action. The feed starts in January 2025, so older rules are missing.
AWSAWS WAF Managed Rules
We found no public statement from this vendor naming this CVE. That is not proof of no protection: generic rules may still catch it. AWS often describes a vulnerability without naming its CVE (for example "Log4j"). We count only entries that name the CVE, so AWS coverage is understated.
Microsoft AzureFront Door and Application Gateway WAF (DRS)
We found no public statement from this vendor naming this CVE. That is not proof of no protection: generic rules may still catch it. The rule tables name CVEs but carry no dates, so Azure is left out of every time-to-rule figure.
Google CloudCloud Armor preconfigured WAF rules
We found no public statement from this vendor naming this CVE. That is not proof of no protection: generic rules may still catch it. Google names few CVEs: the release notes start in May 2024 and the rules reference lists CVEs without dates. Its cve-canary rules are opt-in.
FastlyNext-Gen WAF virtual patches
The CVE predates the oldest entry in this vendor's public feed, so a rule may exist that we cannot see.
F5Attack signatures (Distributed Cloud WAF)
First rule 2026-07-07, 109 days after the CVE was published.
Added: signature 200204067 "Langflow Code Injection (2)" (Server Side Code Injection, risk High), systems: Other Web Server. References: CVE-2026-33017.
AkamaiApp & API Protector (Adaptive Security Engine)
This vendor publishes no machine-readable rule changelog we can check.
OWASP CRSCore Rule Set (open source, used inside many WAFs)
We found no public statement from this vendor naming this CVE. That is not proof of no protection: generic rules may still catch it. CRS rarely names CVEs: it relies on generic detections. Our own lab measures what it actually blocks.
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