Active exploitation of IBM Langflow and N-able vulnerabilities triggers CISA emergency updates

Summary

CISA announced on August 4, 2026, that three new vulnerabilities have been added to its Known Exploited Vulnerabilities (KEV) catalog due to active exploitation. The additions include a critical flaw in IBM Langflow OSS that allows unauthenticated remote code execution, an authentication bypass in N-able N-central, and a sensitive data encryption issue in Apache Tomcat.

Under the new Binding Operational Directive 26-04, federal agencies must prioritize these specific vulnerabilities for rapid remediation. While the directive applies to Federal Civilian Executive Branch (FCEB) agencies, CISA advises all organizations to treat KEV entries as high-priority risks.

Technical details: IBM Langflow RCE

The most severe vulnerability, CVE-2026-9198, carries a CVSS score of 9.8. It allows an unauthenticated attacker to gain full control over default Langflow OSS deployments by chaining two distinct endpoints.

First, the attacker targets /api/v1/auto_login, which mints SUPERUSER bearer tokens to any network caller without authentication. Once a token is obtained, the attacker can access the /api/v1/validate/code endpoint. This endpoint uses exec() to process user code, including Python decorators, default arguments, and annotations at function definition time. By submitting malicious code through this validator, an attacker achieves arbitrary command execution on the host system.

This exploit path is available in all default deployments where the auto-login feature remains enabled and the validation endpoint is network-accessible.

Affected products and fixed versions

Exploitation status

All three vulnerabilities listed below are currently being exploited in the wild:

• IBM Langflow OSS (CVE-2026-9198): Allows unauthenticated remote code execution via token minting and code injection.
• N-able N-central (CVE-2026-18556): An authentication bypass vulnerability using an alternate path or channel.
• Apache Tomcat (CVE-2026-34486): A missing encryption of sensitive data flaw caused by a fix for CVE-2026-29146 that allows the EncryptInterceptor to be bypassed.

Defender guidance

Defenders should prioritize these updates immediately, as the vulnerabilities are actively being used against targets.

For IBM Langflow OSS users, upgrade to version 1.10.1 immediately. If an upgrade is not possible, ensure the auto-login feature is disabled and that the /api/v1/validate/code endpoint is not accessible over the network.

N-able N-central administrators should update their environments to address the authentication bypass vulnerability affecting versions through 2026.1.

Apache Tomcat users must upgrade to version 11.0.21, 10.1.54, or 9.0.117 to prevent the bypass of the EncryptInterceptor.