Quick answers
- Is CVE-2026-79742 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-79742 being exploited in the wild.
- How severe is CVE-2026-79742?
- High severity, with a CVSS score of 8.8, published 10 September 2026.
- Which products and versions are affected?
- IBM Langflow OSS 1.0.0 through 1.11.5.
- Is there a fix for CVE-2026-79742?
- No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
- How is CVE-2026-79742 attacked?
- It is attacked over the network, in a software library.
- Am I affected by CVE-2026-79742?
- Check whether you run IBM Langflow OSS or Langflow at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
Technical details
The vulnerability is a code injection flaw resulting from an incomplete environment variable blocklist in the MCP stdio validator. Specifically, the OPENSSL_CONF environment variable is not blocked, allowing an attacker to set it to point to a malicious OpenSSL configuration file that loads arbitrary native code via OpenSSL engine loading. The vulnerability requires authentication but operates over the network with no additional user interaction. An authenticated attacker can construct a flow with an MCP Tools component using a local stdio subprocess transport to execute arbitrary OS commands at the privilege level of the Langflow application process, bypassing server-side code execution controls. Patched versions are available; users should upgrade to version 1.11.6 or later.
Affected products
- IBM Langflow OSS 1.0.0 through 1.11.5
Timeline
- 2026-09-10: disclosed: CVE-2026-79742 published
- 2026-09-10: other: Part of broader Langflow security bulletin covering multiple RCE vulnerabilities