CVE-2026-16526
Description
A flaw in the PCP linux_sockets module exposes an unsecured internal connection. An attacker with initial code execution can exploit this to escalate privileges and execute arbitrary commands as root.
Statement
This is an Important privilege escalation vulnerability in PCP where an attacker can escalate privileges from the pcp user to root. This flaw requires a prior linux_sockets command injection vulnerability and a non-default configuration where the linux_sockets PMDA is loaded as a DSO in PMCD. Exploitation can occur locally or remotely depending on the pmcd and pmproxy configurations.
Mitigation
To mitigate this vulnerability, ensure that the `linux_sockets` PMDA is not configured to load as a Dynamic Shared Object (DSO) within PMCD. The default configuration for this PMDA is daemon mode, which is not affected by this flaw. Review your `pmcd.conf` file to confirm the `linux_sockets` PMDA is not loaded as a DSO. If changes are made to `pmcd.conf`, a restart of the `pmcd` service is required for them to take effect.
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 | 8.8 | N/A | 8.8 |
| Attack Vector | Network | N/A | Network |
| Attack Complexity | Low | N/A | Low |
| Privileges Required | Low | N/A | Low |
| User Interaction | None | N/A | None |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | High | N/A | High |
| Integrity Impact | High | N/A | High |
| Availability Impact | High | N/A | High |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
cve.org: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Understanding the Weakness (CWE)
Confidentiality,Integrity
Technical Impact: Read Application Data; Modify Application Data
Acknowledgements
Red Hat would like to thank Francisco Alisson Bezerra (TIM Security Red Team Research, TIM S.p.A), Lucas Gabriel Alves (TIM Security Red Team Research, TIM S.p.A), and Massimiliano Brolli (TIM Security Red Team Research, TIM S.p.A) for reporting this issue.
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