Bug 2506026 (CVE-2026-16526)

Summary:	CVE-2026-16526 PCP: PCP: Privilege escalation to root via linux_sockets PMDA vulnerability
Product:	[Other] Security Response	Reporter:	OSIDB Bzimport <bzimport>
Component:	vulnerability	Assignee:	Product Security <prodsec-ir-bot>
Status:	NEW ---	QA Contact:
Severity:	high	Docs Contact:
Priority:	high
Version:	unspecified	CC:	kgaikwad, rhel-process-autobot, security-response-team, watson-tool-maintainers
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	---
Doc Text:	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.	Story Points:	---
Clone Of:		Environment:
Last Closed:		Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:	2511464
Bug Blocks:
Deadline:	2026-07-30

Description OSIDB Bzimport 2026-07-22 07:26:46 UTC

Summary: When the linux_sockets PMDA is loaded as a DSO inside PMCD, code execution
achieved via Vulnerability 3 (network.persocket.filter injection) can be escalated from user
pcp to root. The pmdarootfd Unix socket connection to pmdaroot is created without
O_CLOEXEC, causing all child processes spawned by popen() to inherit it. pmdaroot runs as
root and processes PDUROOT_STARTPMDA_REQ without per-request authentication,
executing attacker-controlled arguments via execvp() as root.
Prerequisites:
• Vulnerability 3 (linux_sockets command injection) required for initial code execution
- exploitable either locally via pmcd (TCP 44321, localhost only by default) or
remotely via the pmproxy REST API (TCP 44322, all interfaces by default, no
authentication required). linux_sockets
• PMDA loaded as DSO in PMCD (requires explicit configuration in pmcd.conf; default
is daemon mode).

Comment 1 errata-xmlrpc 2026-08-17 10:32:46 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8

Via RHSA-2026:55560 https://access.redhat.com/errata/RHSA-2026:55560

Comment 2 errata-xmlrpc 2026-08-17 19:41:03 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9

Via RHSA-2026:55740 https://access.redhat.com/errata/RHSA-2026:55740

Comment 3 errata-xmlrpc 2026-08-17 19:46:29 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 10

Via RHSA-2026:55617 https://access.redhat.com/errata/RHSA-2026:55617

Comment 4 Jon Orris 2026-09-28 04:02:30 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 10.0 Extended Update Support

Via RHSA-2026:72273 https://access.redhat.com/errata/RHSA-2026:72273

Comment 5 Jon Orris 2026-09-28 04:58:13 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9.6 Extended Update Support

Via RHSA-2026:72272 https://access.redhat.com/errata/RHSA-2026:72272

Comment 6 Jon Orris 2026-09-28 15:13:21 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions

Via RHSA-2026:72594 https://access.redhat.com/errata/RHSA-2026:72594

Comment 7 Jon Orris 2026-09-28 15:14:39 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9.4 Update Services for SAP Solutions

Via RHSA-2026:72593 https://access.redhat.com/errata/RHSA-2026:72593

Comment 8 Jon Orris 2026-09-30 07:56:26 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions
  Red Hat Enterprise Linux 8.8 Telecommunications Update Service

Via RHSA-2026:73767 https://access.redhat.com/errata/RHSA-2026:73767

Comment 10 Jon Orris 2026-10-01 22:45:49 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support
  Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On

Via RHSA-2026:74613 https://access.redhat.com/errata/RHSA-2026:74613

Comment 11 Jon Orris 2026-10-01 22:52:30 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support
  Red Hat Enterprise Linux 8.6 Extended Update Support Long-Life Add-On

Via RHSA-2026:74612 https://access.redhat.com/errata/RHSA-2026:74612