CVE-2026-16524 Red Hat CVE debrief

Who should care

System administrators and security teams responsible for PCP installations, especially in environments where metrics are refreshed from untrusted sources, should assess exposure and apply necessary patches.

Why it matters

CVE-2026-16524 is a command injection flaw in PCP's linux_sockets PMDA that allows attackers to execute arbitrary commands. Defenders should verify exposure, restrict access to metrics refresh, and apply Red Hat errata.

• Potential for attackers to execute arbitrary commands as the PMDA user
• Possible disruption of system operations due to unauthorized command execution
• Need for verification of exposure and application of patches

Technical summary

The linux_sockets PMDA in PCP is vulnerable to command injection via the network.persocket.filter metric. This allows attackers to execute arbitrary commands as the PMDA user when metrics are refreshed. The vulnerability is caused by a lack of proper validation of user input, allowing malicious shell metacharacters to be injected into the system. Defenders should prioritize verifying exposure of PCP's linux_sockets PMDA in their environment, especially where metrics are refreshed from untrusted sources, and apply the necessary patches.

Defensive priority

Defenders should prioritize verifying exposure of PCP's linux_sockets PMDA in their environment, especially where metrics are refreshed from untrusted sources.

Recommended defensive actions

• Verify exposure of PCP's linux_sockets PMDA in the environment
• Restrict access to metrics refresh from untrusted sources
• Apply Red Hat errata RHSA-2026:55560, RHSA-2026:55617, RHSA-2026:55740, RHSA-2026:72272, RHSA-2026:72273, RHSA-2026:72593, and RHSA-2026:72594
• Review compensating controls for exposed systems while remediation is scheduled and verified
• Check relevant monitoring, detection, and logs for exposed assets that need extra review
• Track exceptions, retest remediated assets, and close the item only after evidence is documented
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up

Evidence notes

The CVE record and NVD entry provide details on the command injection flaw in PCP's linux_sockets PMDA. Red Hat has provided several errata related to this vulnerability, including RHSA-2026:55560, RHSA-2026:55617, RHSA-2026:55740, RHSA-2026:72272, RHSA-2026:72273, RHSA-2026:72593, and RHSA-2026:72594. The vulnerability allows attackers to execute arbitrary commands as the PMDA user when metrics are refreshed. Defenders should verify exposure, restrict access to metrics refresh, and apply the necessary patches.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.