CVE-2026-19302: 
Homebrew vulnerability analysis and mitigation

CVE-2026-19302 is a symlink traversal vulnerability in IBM Langflow OSS that allows a remote authenticated attacker to obtain sensitive information due to improper validation of symbolic links. It affects IBM Langflow OSS versions 1.0.0 through 1.11.2 (fixed in 1.11.3). The vulnerability was published on September 4, 2026, with a patch advisory added on September 8, 2026. It carries a CVSS v3.1 base score of 6.5 (Medium) (IBM Advisory).

The root cause is improper validation of symbolic links (CWE-22: Path Traversal), where the application fails to restrict file system access to intended directories when processing symlinks. An authenticated attacker with low privileges can craft requests that cause the application to follow symbolic links pointing outside the intended directory scope, thereby reading arbitrary files on the server. No user interaction is required, and the attack is conducted over the network with low complexity. Attack patterns associated with this vulnerability include path traversal techniques such as manipulating web input to file system calls and using encoded slash variants to bypass validation logic (IBM Advisory).

Successful exploitation results in a high confidentiality impact — an attacker can read sensitive files outside the intended directory, potentially exposing credentials, configuration files, or other sensitive server-side data. Integrity and availability are not directly affected by this vulnerability. The scope is unchanged, meaning the impact is confined to the vulnerable component, but data exposure could facilitate further attacks or privilege escalation (IBM Advisory).

There is currently no public proof-of-concept exploit and no evidence of in-the-wild exploitation for CVE-2026-19302. The EPSS score is approximately 0.475%, indicating a low probability of exploitation in the near term. The NVD SSVC assessment classifies exploitation as "none" and the attack as non-automatable. No threat actor attribution or CISA KEV catalog listing has been identified (IBM Advisory).

IBM has released a fix in Langflow OSS version 1.11.3; users should upgrade immediately from any version in the 1.0.0–1.11.2 range. As interim mitigations, administrators should implement strict symlink validation at the OS or application level, restrict file system permissions for the Langflow service account to limit accessible directories, and monitor file access logs for unusual symlink-related activity. The official IBM advisory provides further guidance (IBM Advisory).