Bug 2511464 - CVE-2026-16526 pcp: PCP: Privilege escalation to root via linux_sockets PMDA vulnerability [fedora-all]
Summary: CVE-2026-16526 pcp: PCP: Privilege escalation to root via linux_sockets PMDA ...
Keywords:
Status: CLOSED CURRENTRELEASE
Alias: None
Product: Fedora
Classification: Fedora
Component: pcp
Version: rawhide
Hardware: Unspecified
OS: Unspecified
high
high
Target Milestone: ---
Assignee: William Cohen
QA Contact: Fedora Extras Quality Assurance
URL:
Whiteboard: {"flaws": ["612ff6fb-8a0f-4c60-bc81-1...
Depends On:
Blocks: CVE-2026-16526
TreeView+ depends on / blocked
 
Reported: 2026-08-05 12:05 UTC by Srikanth Balasubramanian
Modified: 2026-08-07 20:13 UTC (History)
7 users (show)

Fixed In Version: pcp-7.2.0-1.fc45
Clone Of:
Environment:
Last Closed: 2026-08-07 20:13:15 UTC
Type: ---
Embargoed:


Attachments (Terms of Use)

Description Srikanth Balasubramanian 2026-08-05 12:05:21 UTC
Disclaimer: Community trackers are created by Red Hat Product Security team on a best effort basis. Package maintainers are required to ascertain if the flaw indeed affects their package, before starting the update process.

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 William Cohen 2026-08-07 20:13:15 UTC
This CVE has been addressed in the new pcp-7.2.0-1 RPM builds available for Fedora Rawhide, Fedora 44, and Fedora 43.


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