CISA KEV Critical Injection exploit reference

CVE-2026-33017 — Langflow Code Injection Vulnerability

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.

Published Mar 20, 2026 · Updated Oct 13, 2026 · Sources: CISA Known Exploited Vulnerabilities, NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP, GitHub Security Advisories · CNA: GitHub_M

Urgent

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

CISA KEV · Mar 25, 2026 Detection templates (Nuclei) · 1 Metasploit modules · 1 Exploit-DB · 1 Proofs of concept on GitHub · 26

How the score was calculated

Confirmed exploitation (CISA KEV)+35
Public exploit/PoC (nuclei, metasploit, exploitdb, github)+20
EPSS 24.8% (30-day exploitation probability)+15
Technical severity (critical)+10
Automatable exploitation (SSVC)+3

The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.

Exploitation

Confirmed

CISA KEV, listed Mar 25, 2026

EPSS FIRST

24.76%

ahead of 98% of scored CVEs · Oct 14, 2026

Affects

Langflow

CVSS base

9.8

Critical · 4 source(s)

CISA SSVC assessment CISA

Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.

Exploitation

Active

none · proof-of-concept · active

Automatable

Yes

can an attacker script the kill-chain steps

Technical impact

Total

partial · total control of the vulnerable component

Remediation

Fixes and mitigations documented by the sources — linked to the original advisory.

Documented patch — github.com (NIST National Vulnerability Database)
Documented mitigation — github.com (NIST National Vulnerability Database)
Pip Langflow: fixed in version 1.9.0 — github.com (GitHub Security Advisories)

CISA required action 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.

US federal deadline: Apr 8, 2026 — passed 190 day(s) ago

First 24 hours

Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.

Identify exposed assets running the affected vendor/product/version combinations (Langflow Langflow, Langflow-ai Langflow, Pip Langflow).
Treat as emergency remediation: the CVE is in CISA KEV (confirmed exploitation).
The attack is network-based and needs no privileges: restrict exposure (ACLs, VPN, WAF) until patched.
Apply the fixed version or the patch documented under Remediation.
EPSS ahead of 98% of scored CVEs: prioritize it in the patch queue.
Search available logs for exploit probes matching the vulnerability class (injection), errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

Vendor	Product	Versions	Status	Source
Langflow	Langflow	< 1.8.2	Vulnerable	NIST National Vulnerability Database
Langflow-ai	Langflow	version < 1.9.0	Vulnerable	CVE Program (cve.org) e CISA ADP
Pip	Langflow	≤ 1.8.2	Vulnerable	GitHub Security Advisories

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Attack vector

Network

Attack complexity

Low

Privileges required

None

User interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Every base score collected

Sources score independently and may disagree; each row says who scored it and under which version.

Score	Version	Severity	Expl.	Impact	Scored by
9.3	CVSS 4.0	Critical	—	—	security-advisories@github.com via NIST National Vulnerability Database
9.3	CVSS 4.0	Critical	—	—	GitHub_M via CVE Program (cve.org) e CISA ADP
9.8	CVSS 3.1	Critical	3.9	5.9	nvd@nist.gov via NIST National Vulnerability Database
9.8	CVSS 3.1	Critical	—	—	GitHub, Inc. via GitHub Security Advisories

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H (score shown at the top: nvd@nist.gov)

Weakness MITRE

Weakness class according to MITRE’s CWE catalog.

CWE-94 · Code Injection

Other CVEs with this weakness →

CISA KEV details CISA

CISA lists a CVE once it has evidence of exploitation against real targets.

Listed

Mar 25, 2026

Federal deadline

Apr 8, 2026

passed 190 day(s) ago

Ransomware use

Unknown

CISA records ransomware use only for campaigns it has confirmed, so “Unknown” means unrecorded, not ruled out. The deadline binds US federal agencies; for everyone else it is a reference date.

Public exploits, PoCs and detection templates

Public code that demonstrates or tests the flaw raises the odds of mass exploitation — and Nuclei templates help find vulnerable assets in your environment.

Detection templates (Nuclei)

Langflow < 1.9.0 - Remote Code Execution

Metasploit modules

Langflow Unauth RCE excellent Mar 20, 2026

Exploit-DB

Langflow 1.9.0 - RCE Jul 8, 2026

Proofs of concept on GitHub — 26 repositories; showing the 10 most starred

Langflow RCE ★ 11 Mar 31, 2026
CVE-2026-33017 - An unauthenticated remote code execution in Langflow <= 1.8.1 via Public Flow Build Endpoint ★ 10 Mar 21, 2026
CVE-2026-33017: Unauthenticated RCE in Langflow ★ 5 Mar 27, 2026
Python POC, Exploit for CVE-2026-33017 ★ 2 Jul 2, 2026
CVE-2026-33017 exploitation tool for Langflow <1.9.0. Features reverse shells, command execution, file operations, persistence, and automated testing. Validates critical RCE vulnerability impact. For authorized security assessments only. ★ 2 Jul 19, 2026
The vulnerability in Langflow 1.8.1 and earlier allows a remote, unauthenticated attacker to achieve arbitrary command execution on the host. ★ 1 Mar 21, 2026
Jorrit-VM/CVE-2026-33017 ★ 1 Apr 20, 2026
CVE-2026-33017 Exploit | by infrar3d ★ 1 Jul 16, 2026
CVE-2026-33017: Langflow Unauthenticated RCE PoC ★ 1 Aug 13, 2026
yym8538/CVE-2026-33017 ★ 1 Aug 21, 2026

Warning: public PoCs are sometimes disguised malware. Use them only for authorized testing in an isolated environment. This portal does not host exploit code — it only points to the sources.

EPSS over time FIRST

Oct 12, 2026 → Oct 14, 2026 · 3 reading(s) · max 24.76%

Detection

Read off the CVSS vector and the weakness class. Starting points, not tested rules.

Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).
Look for parameters with command/query metacharacters and unexpected child processes of the service.
Hunt retroactively in logs from before Mar 25, 2026 (KEV listing): exploitation may have started earlier.

web/proxy/WAF logsnetwork IDS/IPSapplication logsendpoint telemetry (EDR)

Timeline

What happened to this CVE, newest first.

2026
Fix documented
Oct 13, 2026 · GitHub Security Advisories
Affected products added · pip/langflow
Oct 13, 2026 · GitHub Security Advisories
Affected products added · langflow-ai/langflow
Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
SSVC assessment updated
Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
Record published
Oct 13, 2026
Fix documented
Oct 13, 2026 · NIST National Vulnerability Database
Affected products added · langflow/langflow
Oct 13, 2026 · NIST National Vulnerability Database
CVSS changed · 9.8
Oct 13, 2026 · NIST National Vulnerability Database
Source status changed · → Analyzed
Oct 13, 2026 · NIST National Vulnerability Database
Added to CISA KEV (detected)
Oct 13, 2026 · CISA Known Exploited Vulnerabilities
Record created in this database
Oct 13, 2026 · CISA Known Exploited Vulnerabilities
Added to CISA KEV catalog
Mar 24, 2026 · CISA
CVE published
Mar 20, 2026 · GitHub_M

Source activity

Repeated readings are counted rather than listed.

2× References added · Oct 13, 2026 – Oct 13, 2026
1× Official description updated · Oct 13, 2026 – Oct 13, 2026

References

12 on the record

github.com/langflow-ai/langflow/security/advisories/GHSA-vwmf-pq79-vjvx
Exploit, Mitigation, Vendor Advisory, x_refsource_CONFIRM, NIST National Vulnerability Database
github.com/langflow-ai/langflow/commit/73b6612e3ef25fdae0a752d75b0fabd47328d4f0
Patch, x_refsource_MISC, NIST National Vulnerability Database
www.cisa.gov/known-exploited-vulnerabilities-catalog
US Government Resource, NIST National Vulnerability Database
www.sysdig.com/blog/cve-2026-33017-how-attackers-compromised-langflow-ai-pipelines-i
Press/Media Coverage, NIST National Vulnerability Database
medium.com/@aviral23/cve-2026-33017-how-i-found-an-unauthenticated-rce-in-langfl
Exploit, Third Party Advisory, NIST National Vulnerability Database
github.com/langflow-ai/langflow/pull/12160
GitHub Security Advisories
www.cisa.gov/known-exploited-vulnerabilities-catalog
GitHub Security Advisories
github.com/langflow-ai/langflow/releases/tag/1.8.2
Release Notes, NIST National Vulnerability Database
github.com/advisories/GHSA-rvqx-wpfh-mfx7
Third Party Advisory, x_refsource_MISC, NIST National Vulnerability Database
nvd.nist.gov/vuln/detail/CVE-2026-33017
GitHub Security Advisories
github.com/langflow-ai/langflow/issues/12345
GitHub Security Advisories
github.com/advisories/GHSA-vwmf-pq79-vjvx
GitHub Security Advisories

Elsewhere on this site

Langflow
every CVE for this vendor

2026-03
what else CISA listed that month

Injection
same class

CWE-94
other pages naming this weakness

Related CVEs (same products)

High CVE-2026-97680 Langflow OSS is affected by multiple vulnerabilities 8d
High CVE-2026-97673 Langflow OSS is affected by multiple vulnerabilities 8d
High CVE-2026-97674 Langflow OSS is affected by multiple vulnerabilities 8d
High CVE-2026-97676 Langflow OSS is affected by multiple vulnerabilities 8d
High CVE-2026-97678 Langflow OSS is affected by multiple vulnerabilities 8d
High CVE-2026-97679 Langflow OSS is affected by multiple vulnerabilities 8d

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record

Text assembled only from the fields above — no additional claims.

What should defenders know first?

CVE-2026-33017 is "Langflow Code Injection Vulnerability", rated Critical. It affects Langflow (Langflow); versions are in the scope table. It is in CISA KEV: there is evidence of real-world exploitation. CVSS 9.8 describes technical severity. EPSS 24.76% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.

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