Calling getnetbyaddr or its reentrant variant while the system’s nsswitch.conf directs glibc to use the DNS backend for network lookups can cause a stack‑based information leak. A zero‑valued network request triggers an out‑of‑bounds read that exposes raw stack data to the configured DNS resolver, compromising confidentiality.

The flaw is present in GNU C Library versions 2.0 through 2.42. Any Linux system or application that links against one of these glibc releases and that has the DNS backend enabled for network lookups is potentially affected; the vulnerability resides in the library itself, not in specific applications.

The CVSS base score of 7.5 indicates moderate to high severity, while the EPSS score is less than 1%, implying a low likelihood of exploitation and the vulnerability is not listed in the CISA KEV catalog. Exploitation requires code to invoke getnetbyaddr with a zero network address and a configuration that forwards the request to the DNS backend, which can be achieved by modifying nsswitch.conf. Attackers capable of altering system configuration or controlling DNS responses are the most likely threat actors.