Skip to main content
VulnerabilityPublished

CVE-2026-12940: IBM Langflow OSS · OS Command Injection

Affects IBM Langflow OSSSource CVE Database V5

0
Compare

Not known to be exploited · CVSS 9.8 Critical.

Data as of 29 Oct 2026, 07:15 UTC

CVSS 3.1 base score
9.8Critical
How severe the flaw is on the 0–10 CVSS scale.
EPSS
0.9% chance of exploitation in 30 days – higher than 60% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 30 Jul 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponized: evidence found.

    Public exploit code: GitHub proofs of concept

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq Mirage: no evidence on record.

    No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), GitHub proofs of concept, the Metasploit, Exploit-DB and nuclei-templates index as of 29 Oct 2026.

What to do

Affected software

ProductAffectedFixed in
IBMLangflow OSSAffected
  • >=1.0.0 <=1.10.1
Fixed in–

CPE configurations (2)

  • cpe:2.3:a:ibm:langflow_oss:1.0.0:*:*:*:*:*:*:*
  • cpe:2.3:a:ibm:langflow_oss:1.10.1:*:*:*:*:*:*:*

AI-suggested

Until an official fix is available, restrict network access to the affected service and monitor for suspicious activity related to environment variable manipulation.

Description

IBM Langflow OSS 1.0.0 through 1.10.1  are vulnerable to unauthenticated remote code execution via environment variable injection in the MCP (Model Context Protocol) stdio launcher. The vulnerability exists in src/lfx/src/lfx/base/mcp/util.py where the DANGEROUS_ENV_VARS blocklist fails to include SHELLOPTS , BASHOPTS , and PS4 environment variables.

References

Community reviews

Loading reviews…