Severity by source
AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Primary rating from NVD.
CVSS VectorNVD
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Lifecycle Timeline
4DescriptionCVE.org
In the Linux kernel, the following vulnerability has been resolved:
eventpoll: defer struct eventpoll free to RCU grace period
In certain situations, ep_free() in eventpoll.c will kfree the epi->ep eventpoll struct while it still being used by another concurrent thread. Defer the kfree() to an RCU callback to prevent UAF.
AnalysisAI
Use-after-free in Linux kernel eventpoll subsystem allows local authenticated attackers with low privileges to achieve high-impact compromise including arbitrary code execution, privilege escalation, or system crash. The vulnerability stems from premature deallocation of the eventpoll structure while still in use by concurrent threads, creating a race condition exploitable on systems running affected kernel versions 6.4 through 6.19.x and 6.6.x through 6.12.x. Vendor patches available across all affected stable branches with EPSS indicating low widespread exploitation probability (0.02%, 5th percentile), though local access requirements limit attack surface to already-authenticated users or containerized environments.
Technical ContextAI
The eventpoll (epoll) subsystem in the Linux kernel provides scalable I/O event notification mechanisms used extensively by high-performance network services and applications. The vulnerability exists in eventpoll.c where the ep_free() function prematurely calls kfree() to deallocate the eventpoll structure (epi->ep) while another concurrent thread may still hold references to it, creating a classic use-after-free condition. This race condition occurs because the original code lacked proper RCU (Read-Copy-Update) synchronization to ensure all threads complete their read-side critical sections before memory reclamation. The fix defers the kfree() operation to an RCU grace period callback, guaranteeing that no thread can access freed memory. This affects systems using epoll file descriptors for event monitoring, which includes most modern Linux servers running web servers, databases, and containerized workloads. CPE data confirms impact across multiple Linux kernel version branches from the 6.4 introduction point forward.
RemediationAI
Upgrade to patched Linux kernel versions immediately: 6.6.136 or later for 6.6.x series, 6.12.83 or later for 6.12.x series, 6.18.24 or later for 6.18.x series, 6.19.14 or later for 6.19.x series, or 7.0 for mainline users. Patches are available from the Linux kernel stable tree at https://git.kernel.org/stable/ with specific fix commits documented in the references. For systems where immediate kernel upgrade is not feasible, implement compensating controls: restrict local user access to trusted administrators only (reduces attack surface by eliminating PR:L threat actors), deploy mandatory access control frameworks (SELinux/AppArmor) with policies preventing unprivileged users from triggering epoll operations in sensitive contexts (adds defense layer but does not eliminate the race condition), and enable kernel address space layout randomization and other exploit mitigations to increase exploitation difficulty (note: determined local attackers with UAF primitives can often bypass ASLR). Monitor systems for abnormal epoll usage patterns or unexpected kernel panics in eventpoll code paths as potential exploitation indicators. Important: compensating controls only reduce risk - they do not fix the underlying race condition, so kernel patching remains the definitive remediation.
Same weakness CWE-401 – Memory Leak
View allSame technique Information Disclosure
View allVendor StatusVendor
SUSE
Severity: High| Product | Status |
|---|---|
| SUSE Linux Enterprise Desktop 15 SP7 | Fixed |
| SUSE Linux Enterprise Desktop 15 SP7 | Fixed |
| SUSE Linux Enterprise High Availability Extension 15 SP7 | Fixed |
| SUSE Linux Enterprise High Availability Extension 15 SP7 | Fixed |
| SUSE Linux Enterprise High Performance Computing 15 SP7 | Fixed |
| SUSE Linux Enterprise High Performance Computing 15 SP7 | Fixed |
| SUSE Linux Enterprise Live Patching 15 SP7 | Fixed |
| SUSE Linux Enterprise Live Patching 15 SP7 | Fixed |
| SUSE Linux Enterprise Micro 5.3 | Fixed |
| SUSE Linux Enterprise Micro 5.3 | Fixed |
| SUSE Linux Enterprise Micro 5.3 | Fixed |
| SUSE Linux Enterprise Micro 5.3 | Fixed |
| SUSE Linux Enterprise Micro 5.4 | Fixed |
| SUSE Linux Enterprise Micro 5.4 | Fixed |
| SUSE Linux Enterprise Micro 5.4 | Fixed |
| SUSE Linux Enterprise Micro 5.4 | Fixed |
| SUSE Linux Enterprise Micro 5.5 | Fixed |
| SUSE Linux Enterprise Micro 5.5 | Fixed |
| SUSE Linux Enterprise Micro 5.5 | Fixed |
| SUSE Linux Enterprise Module for Basesystem 15 SP7 | Fixed |
| SUSE Linux Enterprise Module for Basesystem 15 SP7 | Fixed |
| SUSE Linux Enterprise Module for Development Tools 15 SP7 | Fixed |
| SUSE Linux Enterprise Module for Development Tools 15 SP7 | Fixed |
| SUSE Linux Enterprise Module for Legacy 15 SP7 | Fixed |
| SUSE Linux Enterprise Module for Legacy 15 SP7 | Fixed |
| SUSE Linux Enterprise Module for Public Cloud 15 SP7 | Fixed |
| SUSE Linux Enterprise Module for Public Cloud 15 SP7 | Fixed |
| SUSE Linux Enterprise Real Time 15 SP7 | Fixed |
| SUSE Linux Enterprise Server 15 SP7 | Fixed |
| SUSE Linux Enterprise Server 15 SP7 | Fixed |
| SUSE Linux Enterprise Server 16.0 | Fixed |
| SUSE Linux Enterprise Server 16.0 | Fixed |
| SUSE Linux Enterprise Server 16.1 | Fixed |
| SUSE Linux Enterprise Server for SAP Applications 15 SP7 | Fixed |
| SUSE Linux Enterprise Server for SAP Applications 15 SP7 | Fixed |
| SUSE Linux Enterprise Server for SAP applications 16.0 | Fixed |
| SUSE Linux Enterprise Server for SAP applications 16.0 | Fixed |
| SUSE Linux Enterprise Server for SAP applications 16.1 | Fixed |
| SUSE Linux Enterprise Workstation Extension 15 SP7 | Fixed |
| SUSE Linux Enterprise Workstation Extension 15 SP7 | Fixed |
| SUSE Linux Micro 6.0 | Fixed |
| SUSE Linux Micro 6.0 | Fixed |
| SUSE Linux Micro 6.0 | Fixed |
| SUSE Linux Micro 6.1 | Fixed |
| SUSE Linux Micro 6.1 | Fixed |
| SUSE Linux Micro 6.1 | Fixed |
| SUSE Linux Micro 6.2 | Fixed |
| SUSE Linux Micro 6.2 | Fixed |
| SUSE Real Time Module 15 SP7 | Fixed |
| SUSE Linux Enterprise High Performance Computing 15 SP4 | Fixed |
| SUSE Linux Enterprise High Performance Computing 15 SP4-LTSS | Fixed |
| SUSE Linux Enterprise High Performance Computing 15 SP4-LTSS | Fixed |
| SUSE Linux Enterprise High Performance Computing 15 SP5 | Fixed |
| SUSE Linux Enterprise High Performance Computing 15 SP5-LTSS | Fixed |
| SUSE Linux Enterprise High Performance Computing 15 SP5-LTSS | Fixed |
| SUSE Linux Enterprise Live Patching 12 SP5 | Fixed |
| SUSE Linux Enterprise Live Patching 12 SP5 | Fixed |
| SUSE Linux Enterprise Live Patching 15 SP4 | Fixed |
| SUSE Linux Enterprise Live Patching 15 SP4 | Fixed |
| SUSE Linux Enterprise Live Patching 15 SP5 | Fixed |
| SUSE Linux Enterprise Live Patching 15 SP5 | Fixed |
| SUSE Linux Enterprise Module for Basesystem 15 SP4 | Fixed |
| SUSE Linux Enterprise Module for Basesystem 15 SP5 | Fixed |
| SUSE Linux Enterprise Module for Basesystem 15 SP6 | Fixed |
| SUSE Linux Enterprise Module for Development Tools 15 SP4 | Fixed |
| SUSE Linux Enterprise Module for Development Tools 15 SP5 | Fixed |
| SUSE Linux Enterprise Module for Development Tools 15 SP6 | Fixed |
| SUSE Linux Enterprise Server 11 SP4 LTSS EXTREME CORE | Fixed |
| SUSE Linux Enterprise Server 11 SP4 LTSS EXTREME CORE | Fixed |
| SUSE Linux Enterprise Server 12 SP5 | Fixed |
| SUSE Linux Enterprise Server 12 SP5-LTSS | Fixed |
| SUSE Linux Enterprise Server 12 SP5-LTSS | Fixed |
| SUSE Linux Enterprise Server 12 SP5-LTSS Extended Security | Fixed |
| SUSE Linux Enterprise Server 12 SP5-LTSS Extended Security | Fixed |
| SUSE Linux Enterprise Server 15 SP4 | Fixed |
| SUSE Linux Enterprise Server 15 SP4-LTSS | Fixed |
| SUSE Linux Enterprise Server 15 SP4-LTSS | Fixed |
| SUSE Linux Enterprise Server 15 SP5 | Fixed |
| SUSE Linux Enterprise Server 15 SP5-LTSS | Fixed |
| SUSE Linux Enterprise Server 15 SP5-LTSS | Fixed |
| SUSE Linux Enterprise Server 15 SP6 | Fixed |
| SUSE Linux Enterprise Server 15 SP6-LTSS | Fixed |
| SUSE Linux Enterprise Server 15 SP6-LTSS | Fixed |
| SUSE Linux Enterprise Server LTSS Extended Security 12 SP5 | Fixed |
| SUSE Linux Enterprise Server for SAP Applications 15 SP6 | Fixed |
| SUSE Linux Enterprise Server for SAP Applications 15 SP6 | Fixed |
| SUSE Manager Proxy 4.3 | Fixed |
| SUSE Manager Proxy LTS 4.3 | Fixed |
| SUSE Manager Retail Branch Server 4.3 | Fixed |
| SUSE Manager Retail Branch Server LTS 4.3 | Fixed |
| SUSE Manager Server 4.3 | Fixed |
| SUSE Manager Server LTS 4.3 | Fixed |
| SUSE CaaS Platform 4.0 | Fixed |
| SUSE Enterprise Storage 6 | Fixed |
| SUSE Enterprise Storage 7 | Fixed |
| SUSE Enterprise Storage 7.1 | Fixed |
| SUSE Linux Enterprise Desktop 11 SP4 | Fixed |
| SUSE Linux Enterprise Desktop 12 SP4 | Fixed |
| SUSE Linux Enterprise Desktop 15 SP1 | Fixed |
| SUSE Linux Enterprise Desktop 15 SP2 | Fixed |
| SUSE Linux Enterprise Desktop 15 SP3 | Fixed |
| SUSE Linux Enterprise Desktop 15 SP4 | Fixed |
| SUSE Linux Enterprise Desktop 15 SP5 | Fixed |
| SUSE Linux Enterprise Desktop 15 SP6 | Fixed |
| SUSE Linux Enterprise High Performance Computing 15 SP1 | Fixed |
| SUSE Linux Enterprise High Performance Computing 15 SP1-ESPOS | Fixed |
| SUSE Linux Enterprise High Performance Computing 15 SP1-LTSS | Fixed |
| SUSE Linux Enterprise High Performance Computing 15 SP2 | Fixed |
| SUSE Linux Enterprise High Performance Computing 15 SP2-ESPOS | Fixed |
| SUSE Linux Enterprise High Performance Computing 15 SP2-LTSS | Fixed |
| SUSE Linux Enterprise High Performance Computing 15 SP3 | Fixed |
| SUSE Linux Enterprise High Performance Computing 15 SP3-ESPOS | Fixed |
| SUSE Linux Enterprise High Performance Computing 15 SP3-LTSS | Fixed |
| SUSE Linux Enterprise High Performance Computing 15 SP4-ESPOS | Fixed |
| SUSE Linux Enterprise High Performance Computing 15 SP5-ESPOS | Fixed |
| SUSE Linux Enterprise High Performance Computing 15 SP6 | Fixed |
| SUSE Linux Enterprise Micro 5.0 | Fixed |
| SUSE Linux Enterprise Micro 5.1 | Fixed |
| SUSE Linux Enterprise Micro 5.2 | Fixed |
| SUSE Linux Enterprise Micro 5.2 | Fixed |
| SUSE Linux Enterprise Module for Basesystem 15 SP1 | Fixed |
| SUSE Linux Enterprise Module for Basesystem 15 SP2 | Fixed |
| SUSE Linux Enterprise Module for Basesystem 15 SP3 | Fixed |
| SUSE Linux Enterprise Module for Development Tools 15 SP1 | Fixed |
| SUSE Linux Enterprise Module for Development Tools 15 SP2 | Fixed |
| SUSE Linux Enterprise Module for Development Tools 15 SP3 | Fixed |
| SUSE Linux Enterprise Real Time 15 SP2 | Fixed |
| SUSE Linux Enterprise Real Time 15 SP3 | Fixed |
| SUSE Linux Enterprise Real Time 15 SP4 | Fixed |
| SUSE Linux Enterprise Real Time 15 SP4 | Fixed |
| SUSE Linux Enterprise Real Time 15 SP5 | Fixed |
| SUSE Linux Enterprise Server 11 SP4 | Fixed |
| SUSE Linux Enterprise Server 11 SP4-LTSS | Fixed |
| SUSE Linux Enterprise Server 12 SP4 | Fixed |
| SUSE Linux Enterprise Server 12 SP4-ESPOS | Fixed |
| SUSE Linux Enterprise Server 12 SP4-LTSS | Fixed |
| SUSE Linux Enterprise Server 12 SP4-LTSS | Fixed |
| SUSE Linux Enterprise Server 15 SP1 | Fixed |
| SUSE Linux Enterprise Server 15 SP1-BCL | Fixed |
| SUSE Linux Enterprise Server 15 SP1-LTSS | Fixed |
| SUSE Linux Enterprise Server 15 SP1-LTSS | Fixed |
| SUSE Linux Enterprise Server 15 SP2 | Fixed |
| SUSE Linux Enterprise Server 15 SP2-BCL | Fixed |
| SUSE Linux Enterprise Server 15 SP2-LTSS | Fixed |
| SUSE Linux Enterprise Server 15 SP2-LTSS | Fixed |
| SUSE Linux Enterprise Server 15 SP3 | Fixed |
| SUSE Linux Enterprise Server 15 SP3-BCL | Fixed |
| SUSE Linux Enterprise Server 15 SP3-LTSS | Fixed |
| SUSE Linux Enterprise Server 15 SP3-LTSS | Fixed |
| SUSE Linux Enterprise Server for SAP Applications 12 SP4 | Fixed |
| SUSE Linux Enterprise Server for SAP Applications 15 SP1 | Fixed |
| SUSE Linux Enterprise Server for SAP Applications 15 SP2 | Fixed |
| SUSE Linux Enterprise Server for SAP Applications 15 SP3 | Fixed |
| SUSE Linux Enterprise Server for SAP Applications 15 SP4 | Fixed |
| SUSE Linux Enterprise Server for SAP Applications 15 SP4 | Fixed |
| SUSE Linux Enterprise Server for SAP Applications 15 SP5 | Fixed |
| SUSE Linux Enterprise Server for SAP Applications 15 SP5 | Fixed |
| SUSE Manager Proxy 4.0 | Fixed |
| SUSE Manager Proxy 4.1 | Fixed |
| SUSE Manager Proxy 4.2 | Fixed |
| SUSE Manager Retail Branch Server 4.0 | Fixed |
| SUSE Manager Retail Branch Server 4.1 | Fixed |
| SUSE Manager Retail Branch Server 4.2 | Fixed |
| SUSE Manager Server 4.0 | Fixed |
| SUSE Manager Server 4.1 | Fixed |
| SUSE Manager Server 4.2 | Fixed |
| SUSE OpenStack Cloud 9 | Fixed |
| SUSE OpenStack Cloud Crowbar 9 | Fixed |
| SUSE Real Time Module 15 SP4 | Fixed |
| SUSE Real Time Module 15 SP5 | Fixed |
| openSUSE Leap 15.3 | Fixed |
| openSUSE Leap 15.4 | Fixed |
| openSUSE Leap 15.4 | Fixed |
| openSUSE Leap 15.5 | Fixed |
| openSUSE Leap 15.5 | Fixed |
| openSUSE Leap 15.6 | Fixed |
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External POC / Exploit Code
Leaving vuln.today
EUVD-2026-27558