Executive brief
A security vulnerability has been identified in Performance Co-Pilot (PCP), a system monitoring toolkit used in Red Hat Enterprise Linux and OpenShift environments. An unauthenticated attacker can send specially crafted network requests to the monitoring proxy service to bypass security controls and modify system metrics. This flaw can be exploited to gain full control over the affected server, potentially leading to data theft, service disruption, or unauthorized access to the broader corporate network.
Technical details
A vulnerability exists in the pmproxy REST API of Performance Co-Pilot (PCP) due to an authentication bypass in the /store endpoint. The root cause is 'dead code' where authentication flags (-S and -Q) are present in the source logic but missing from the command-line option parsing strings, making it impossible to enable authentication for this endpoint. An unauthenticated attacker can use a crafted hostspec parameter to force pmproxy to connect to the pmcd daemon via Unix sockets. This bypasses pmcd host-based access rules (which typically only cover IP transports), allowing the attacker to overwrite PMDA metrics. When combined with the linux_sockets PMDA, this can lead to arbitrary code execution and full system takeover.
Affected products
- Red Hat Enterprise Linux 7 affected
- Red Hat Enterprise Linux 8 affected
- Red Hat Enterprise Linux 9 affected
- Red Hat Enterprise Linux 10 affected
- Red Hat OpenShift Container Platform 4 affected
- Performance Co-Pilot Performance Co-Pilot (PCP) all versions including pmproxy
Timeline
- 2026-07-22: other: Reported to Red Hat Bugzilla
- 2026-07-30: disclosed: Public disclosure of CVE-2026-16527