CVE-2026-43958

A flaw was found in rrdcached, a component of rrdtool. A local attacker with access to a rrdcached socket can exploit a stack-based buffer overflow by sending an oversized CREATE request. This vulnerability can lead to a denial of service by crashing the daemon or potentially allow for arbitrary code execution, impacting the integrity and confidentiality of data.

This stack buffer overflow in rrdcached allows a local attacker with socket access to cause a denial of service or potentially execute arbitrary code. The default configuration exposes rrdcached via a local UNIX socket, requiring local access and specific permissions for exploitation. Deployments exposing TCP listeners without proper access controls face a higher risk. The Red Hat Product Security team has rated this vulnerability as having a Moderate severity, this is due to the fact of the attack vector is local and the attacker needs permission to reach out to the UNIX socket in order to exploit this flaw.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

Restrict access to the rrdcached UNIX socket using filesystem permissions and group ownership to prevent untrusted local users from connecting. Avoid exposing rrdcached on TCP listeners unless strictly necessary, and ensure any such listeners are protected by network access controls. Additionally, run the rrdcached daemon as an unprivileged user and group using the -U and -G options to minimize impact in case of compromise. If rrdcached is restarted or reloaded, these configurations will be reapplied.