CVE-2026-12940: IBM Langflow OSS · OS Command Injection
Affects IBM Langflow OSSSource CVE Database V5
Not known to be exploited · CVSS 9.8 Critical.
Data as of 29 Oct 2026, 07:15 UTC
- 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:HExploitation evidence
Disclosed: evidence found.
CVE published 30 Jul 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: evidence found.
Public exploit code: GitHub proofs of concept
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by 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
| Product | Affected | Fixed in |
|---|---|---|
| IBMLangflow OSS | Affected
| 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.