CVE-2026-16527
Description
An unauthenticated remote attacker can bypass access controls by sending crafted requests to the PCP pmproxy /store endpoint. This allows the attacker to overwrite any PMDA metric, leading to arbitrary code execution and system takeover.
Statement
This is an Important flaw in Performance Co-Pilot (PCP) pmproxy that allows an unauthenticated remote attacker to bypass pmcd access controls. By sending crafted requests to the /store endpoint, an attacker can write to any Performance Metrics Domain Agent (PMDA) metric, potentially leading to arbitrary code execution if pmproxy is running and reachable on its default port.
Mitigation
To mitigate this issue, restrict network access to the pmproxy service (port 44322/TCP) to trusted hosts only using firewall rules. If pmproxy functionality is not required, disable the service. Disabling the service will prevent remote access to performance metrics via pmproxy. To disable the service, run: `sudo systemctl stop pmproxy` and `sudo systemctl disable pmproxy`. If firewalling, ensure to reload the firewall rules after making changes.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 7.3 | N/A | 7.3 |
| Attack Vector | Network | N/A | Network |
| Attack Complexity | Low | N/A | Low |
| Privileges Required | None | N/A | None |
| User Interaction | None | N/A | None |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | Low | N/A | Low |
| Integrity Impact | Low | N/A | Low |
| Availability Impact | Low | N/A | Low |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
cve.org: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
Understanding the Weakness (CWE)
Access Control,Other
Technical Impact: Gain Privileges or Assume Identity; Varies by Context
Exposing critical functionality essentially provides an attacker with the privilege level of that functionality. The consequences will depend on the associated functionality, but they can range from reading or modifying sensitive data, accessing administrative or other privileged functionality, or possibly even executing arbitrary code.
Frequently Asked Questions
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