basicsecurity.net
Proof, not just disclosure.
Threats / Langflow / CVE-2026-33017
CVE-2026-33017 · EUVD no mirror located · GCVE no mirror located Verified 2026-08-04

Langflow vulnerability

Langflow contains a code injection vulnerability allowing unauthenticated construction of public flows, enabling arbitrary code execution without proper access controls.

Verdict

Today item — known-exploited.

An unauthenticated attacker can inject and execute arbitrary code through Langflow's public flow builder, bypassing authentication mechanisms. This vulnerability is actively exploited in the wild and poses significant risk to deployed instances.

CISA KEV Yes · 2026-03-255EPSS 0.99836 (verify live)6Exploit Weaponized · public PoC7CVSS 9.33CISA SSVC Exploitation: active · Automatable: yes · Impact: total4
01

Is it exploitable?

— the evidence, ranked above the score
Exploit available
Fully weaponized — public exploit code is cataloged for this vulnerability.We link the existence of the exploit; we do not host or redistribute payloads.
Reported exploitation
12 independent public reports of in-the-wild exploitation are cataloged.Distinct reporting sources (vendor, incident response, government); open them for the underlying claims.
Exploited in the wild
Listed in the CISA Known Exploited Vulnerabilities catalog (added 2026-03-25).
CISA KEV ↗Confirmed
Probability (EPSS)
EPSS 0.99836 — modeled likelihood of exploitation activity.EPSS is a daily-changing model output — open the source for today's value.
Severity / affected
CVSS 9.3 (CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:L/SI:L/SA:L) · Affected: Langflow, Langflow. Confirm exact fixed builds in the vendor advisory.CVSS — CNA-assigned (CVE.org), version 4.0, set at disclosure.
CVE.org ↗Reported
Weakness (CWE)
Mapped to CWE-94 Code Injection, CWE-95 Eval Injection, CWE-306 Missing Authentication — weakness family: Injection, Authentication.CWE — CNA-assigned (CVE.org); the weakness class drives how the flaw is exploited.
CVE.org ↗Reported
CISA SSVC (triage disposition)
Exploitation: active · Automatable: yes · Technical Impact: totalCISA's own stakeholder-specific triage inputs, published in the CVE record (CISA Coordinator role). NOTE: this is CISA's three decision points; the final Act/Attend/Track decision also requires a Mission & Well-being input not published here, so no overall decision is asserted.
CISA-ADP ↗Reported
Currency of the record
CISA added this to its KEV catalog 5 days after the CVE record was published.KEV lag = CISA-KEV dateAdded − CVE.org datePublished; a floor on how long the known-exploited flaw sat in the public record before the federal catalog listed it. Severity/weakness here is CNA- or CISA-assigned (current at disclosure), independent of NVD's analysis backlog.
Public exploit available
Public exploit tooling is catalogued for this CVE (a public proof-of-concept / detection template). Catalog entries: nuclei template. We link the catalog page(s) only — no payload or code is hosted or restated here.Link, never host — the catalog page is the source; basicsecurity.net does not redistribute payloads.
nuclei ↗Confirmed
02

Who’s exploiting it?

— attribution turns risk into urgency
Attribution not established

No confirmed (advisory-backed) threat-actor attribution is established for this record. Absence of a named actor is not absence of compromise — see Coverage & confidence.

03

Why it matters

— the attack path, told twice: adversary, then board
1

Front door — unauthenticated access narrative 1

Attacker
I identify that Langflow's public flow endpoint lacks authentication enforcement on code injection points.
Business
Attackers gain unrestricted code execution capability on production systems without credentials.
2

Keys to the kingdom — privilege/identity takeover narrative 2

Attacker
I craft malicious flow definitions containing injected code that executes during flow processing.
Business
Arbitrary code runs with the privileges of the Langflow application, compromising data and system integrity.
3

Lateral reach — past segmentation narrative 3

Attacker
I establish persistence or lateral movement by leveraging code execution to access underlying infrastructure.
Business
Breach scope expands beyond Langflow to connected systems, databases, and organizational networks.
04

What to do

— defensible action
  • Remediate per the vendor advisory — confirm the fixed build for your version and verify exposure.1
Say it to the boardA vulnerability with this evidence profile is a defensible budget line, not a backlog ticket — fund the change against the proof above.
05

Coverage & confidence

— what we know, and what we don’t

Established (cited)

  • KEV listing (CISA)
  • EPSS probability (FIRST)
  • Weaponized exploit available (VulnCheck)
  • 12 reported-exploitation source(s)
  • CVSS 9.3 — CNA-assigned (CVE.org)
  • CISA SSVC triage disposition (CVE.org ADP)
  • CWE weakness mapping — CNA-assigned (CVE.org)
  • Public exploit availability
  • Catalogued by GitHub_M (CNA)
  • Coverage gaps — stated, not hidden

  • No EUVD / GCVE mirror in feed — single-authority dependency for the identifier.
  • EPSS & exposure are time-varying; verify live at the source.
  • Threat-actor attribution not established from feed data — absence of a name is not absence of compromise.
  • No finder/reporter credit recorded in the public CVE entry — the work behind this find is unattributed.
  • Disclosure & credit2
    Catalogued by GitHub_MCNA
    Credited with finding itNo finder named in the public CVE record — the work behind this find is unattributed.