CVE-2026-43958 is a stack buffer overflow vulnerability in the rrdcached handle_request_create() function of RRDtool, a utility used for storing and graphing time-series data. The flaw arises from unbounded DS/RRA arguments, enabling local privilege escalation or denial of service. Red Hat Enterprise Linux versions 8 and 10, across various architectures (x86_64, s390x, ppc64le, aarch64), are affected. Red Hat has issued security advisories RHSA-2026:33731 and RHSA-2026:34155 with updated packages that fix this vulnerability. The advisories provide detailed remediation instructions and package updates.

Successful exploitation of this vulnerability allows a local attacker to execute code with elevated privileges or cause a denial of service condition on affected Red Hat Enterprise Linux systems. The impact is limited to local users and does not indicate remote exploitation capability. Red Hat rates the security impact as Moderate.

Red Hat has released official security updates that fix this vulnerability in RRDtool for Red Hat Enterprise Linux 8 and 10. Users should apply the updates provided in advisories RHSA-2026:33731 and RHSA-2026:34155 promptly. Detailed update instructions are available at https://access.redhat.com/articles/11258. No additional mitigation is required beyond applying the official patches.