CVE-2026-45258 FreeBSD CVE debrief

Who should care

System administrators and security teams responsible for managing audio devices and kernel security should be aware of this vulnerability. Unprivileged local users could exploit this vulnerability to gain elevated privileges or cause a DoS. Organizations using affected systems should prioritize patching and monitoring.

Technical summary

The dsp_mmap_single() function did not properly validate user-supplied offset and length values, allowing an overflow that could pass the check. The offset was then narrowed from 64 to 32 bits, resulting in a mapping that extended past the audio buffer into unrelated kernel memory. This vulnerability affects systems with audio devices and world-accessible /dev/dsp device nodes. An unprivileged local user could exploit this vulnerability to read and write kernel memory.

Defensive priority

High priority should be given to patching and mitigating this vulnerability, as it allows unprivileged local users to access kernel memory. System administrators should ensure that audio devices are properly configured and that access to /dev/dsp device nodes is restricted.

Recommended defensive actions

• Apply patches or updates provided by the vendor to address the vulnerability.
• Restrict access to /dev/dsp device nodes to prevent unprivileged local users from exploiting the vulnerability.
• Monitor system logs and kernel activity for potential exploitation attempts.
• Perform regular security audits and vulnerability assessments to identify potential weaknesses.
• Implement compensating controls, such as intrusion detection and prevention systems, to detect and prevent exploitation.

Evidence notes

The CVE record and NVD detail provide information on the vulnerability, including its CVSS score and severity. The source item URL provides additional context and references. The FreeBSD security advisory provides details on the vulnerability and recommended patches.

Official resources