No exploitation reportedFix available

CVE-2026-33873

Q: Is CVE-2026-33873 actively exploited?

Active exploitation of CVE-2026-33873 has not been confirmed. Its EPSS score was 1.8% on 2026-10-23, the estimated probability of exploitation in the next 30 days.

Q: What is the CVSS score for CVE-2026-33873?

CVE-2026-33873 has a CVSS v3 base score of 9.9 (CRITICAL severity), with vector string CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H.

No exploitation reported by the sources we read.

Published2026-03-27
Fixed in1.9.0
WeaknessCWE-94

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

Description

Langflow is a tool for building and deploying AI-powered agents and workflows. Prior to version 1.9.0, the Agentic Assistant feature in Langflow executes LLM-generated Python code during its validation phase. Although this phase appears intended to validate generated component code, the implementation reaches dynamic execution sinks and instantiates the generated class server-side. In deployments where an attacker can access the Agentic Assistant feature and influence the model output, this can result in arbitrary server-side Python execution. Version 1.9.0 fixes the issue.

Timeline

dates in UTC

2026-03-2721:17CVE publishedNVD

Observed activity

isMalicious corpus · updated 2026-10-23 21:37 UTC

Indicators tagged with this CVE, per day0 indicators over 7 days

Block these indicators

Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2026-33873?format=txt
CSV export: https://api.ismalicious.com/edl/cve/CVE-2026-33873?format=csv
TAXII collection of exploited CVEs
The EDL and CSV take an API key on the Pro plan.

Versions per branch

NVD · OSV

Langflow

Branch	Affected	Fixed in	Source
1.9	< 1.9.0	1.9.0	NVD · OSV

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Fix

Update Langflow to 1.9.0

Advisories and patches

github.comMitigation · Vendor Advisory

Detection

Nuclei template: none so far
Exploit-DB: no entry
Proof-of-concept repositories: none listed

Sources

CISA-ADPSSVC decisionnone2026-04-01
OpenCVESSVC decisionnone—
CNACVSS 4.09.3read 2026-10-23
NVDCVSS 3.19.9read 2026-10-23
CNAweakness (CWE)CWE-94read 2026-10-23
FIRST EPSSEPSS score1.8 %2026-10-23
OSVaffected packages—

Technical details

CVSS v3 Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
CVSS 4.0 vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:N/SC:H/SI:H/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Published: 2026-03-27
Last Modified: 2026-06-17
NVD status: Analyzed

Frequently asked questions

What is CVE-2026-33873?

Is CVE-2026-33873 actively exploited?

Active exploitation of CVE-2026-33873 has not been confirmed. Its EPSS score was 1.8% on 2026-10-23, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2026-33873?

CVE-2026-33873 has a CVSS v3 base score of 9.9 (CRITICAL severity), with vector string CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H.

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