The vulnerability resides in the System Security Services Daemon (SSSD), where an unprivileged local user can repeatedly request NSS lookups for nonexistent entries. Because the negative cache lacks a total entry limit and only removes records when a key is rechecked, each lookup can insert a new entry. Over time, the cache can grow without bound, consuming all available memory and eventually causing the responder process to become unresponsive or terminate, which yields a denial‑of‑service condition. The weakness is defined as CWE‑770: Excessive Runtime Resource Consumption.

This flaw affects Red Hat Enterprise Linux distributions 6 through 10 and the Red Hat OpenShift Container Platform 4, as the SSSD packages shipped with these product families contain the vulnerable code. No specific version numbers are listed, so any deployment of the affected SSSD versions within these products is potentially vulnerable.

The CVSS score of 5.5 indicates moderate severity, while the EPSS is not available and the vulnerability is not listed in the CISA KEV catalog. The attack vector is local; an unprivileged user with access to the host can trigger the excess cache growth. Although no public exploit has been demonstrated and no elevation of privilege is required, the impact can be significant: memory exhaustion can degrade or halt other services on the same host, potentially bringing the entire operating system down. Because the exploit requires only local access and the damage is limited to the affected host, the overall risk is considered low to moderate.