Severity by source
AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Local access with low privilege required; netem reorder configuration is an operator prerequisite; impact is availability-only via unbounded kernel queue growth.
Primary rating from NVD.
CVSS VectorNVD
Lifecycle Timeline
5DescriptionNVD
In the Linux kernel, the following vulnerability has been resolved:
net/sched: netem: fix queue limit check to include reordered packets
The queue limit check in netem_enqueue() uses q->t_len which only counts packets in the internal tfifo. Packets placed in sch->q by the reorder path (__qdisc_enqueue_head) are not counted, allowing the total queue occupancy to exceed sch->limit under reordering.
Include sch->q.qlen in the limit check.
AnalysisAI
Unbounded queue growth in the Linux kernel's netem (Network Emulator) traffic control subsystem allows a local low-privileged user to exhaust kernel memory and trigger a denial of service. The flaw exists because netem_enqueue() enforces queue depth limits using only q->t_len (packets in the internal tfifo), while packets placed into sch->q via the reorder path (__qdisc_enqueue_head) are silently excluded from that count, allowing total queue occupancy to grow beyond sch->limit without bound. No public exploit has been identified and the EPSS score of 0.18% (8th percentile) places this in the lowest exploitation-probability tier; however, the vulnerability affects a wide range of active stable kernel branches and patched versions are available.
Technical ContextAI
The netem qdisc (network emulator queuing discipline) is a Linux traffic control module invoked via tc(8) to simulate WAN conditions including delay, jitter, packet loss, duplication, and reordering. It is implemented in net/sched/sch_netem.c and maintains two internal data structures: a time-ordered tfifo heap (q->t_len) for scheduling future transmits, and the standard qdisc queue (sch->q) used when packets are reordered and must be injected at the head of the output queue via __qdisc_enqueue_head. The bug is a missing addend in the queue depth comparison: the guard if (q->t_len >= sch->limit) fails to account for sch->q.qlen, meaning the effective queue can grow to (sch->limit + sch->q.qlen), potentially unbounded under continuous reorder load. No CWE is formally assigned; the closest applicable class is CWE-400 (Uncontrolled Resource Consumption) or CWE-682 (Incorrect Calculation). Affected products are identified by CPE cpe:2.3:a:linux:linux:* across multiple stable branches from 5.4.x through 6.13.
RemediationAI
Apply the vendor-released stable kernel update for the branch in use: upgrade to Linux 5.10.258, 5.15.209, 6.1.175, 6.6.141, 6.12.91, 6.18.33, 7.0.10, or 7.1 as appropriate. Commit-level patches for each branch are indexed at https://git.kernel.org/stable/c/ via the cveorg references above. For systems unable to patch immediately, the most effective compensating control is to ensure no netem qdisc with reordering is configured in production - removing or not deploying the netem qdisc entirely eliminates the vulnerable code path without side effects on non-test workloads. A second control is to restrict CAP_NET_ADMIN capability so that only root can configure traffic control (e.g., disabling unprivileged user namespaces via kernel.unprivileged_userns_clone=0 on affected distros), which prevents low-privilege users from creating or modifying qdiscs; note this may break container networking features that rely on user namespaces. Neither workaround substitutes for patching on systems where netem is legitimately required.
Same technique Information Disclosure
View allVendor StatusVendor
SUSE
Severity: Moderate| Product | Status |
|---|---|
| SUSE Linux Enterprise Desktop 15 SP7 | Affected |
| SUSE Linux Enterprise Desktop 15 SP7 | Affected |
| SUSE Linux Enterprise High Availability Extension 15 SP7 | Affected |
| SUSE Linux Enterprise High Availability Extension 15 SP7 | Affected |
| SUSE Linux Enterprise High Availability Extension 16.0 | Affected |
| SUSE Linux Enterprise High Availability Extension 16.0 | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP7 | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP7 | Affected |
| SUSE Linux Enterprise Live Patching 15 SP7 | Affected |
| SUSE Linux Enterprise Live Patching 15 SP7 | Affected |
| SUSE Linux Enterprise Micro 5.3 | Affected |
| SUSE Linux Enterprise Micro 5.3 | Affected |
| SUSE Linux Enterprise Micro 5.3 | Affected |
| SUSE Linux Enterprise Micro 5.3 | Affected |
| SUSE Linux Enterprise Micro 5.4 | Affected |
| SUSE Linux Enterprise Micro 5.4 | Affected |
| SUSE Linux Enterprise Micro 5.4 | Affected |
| SUSE Linux Enterprise Micro 5.4 | Affected |
| SUSE Linux Enterprise Micro 5.5 | Affected |
| SUSE Linux Enterprise Micro 5.5 | Affected |
| SUSE Linux Enterprise Micro 5.5 | Affected |
| SUSE Linux Enterprise Module for Basesystem 15 SP7 | Affected |
| SUSE Linux Enterprise Module for Basesystem 15 SP7 | Affected |
| SUSE Linux Enterprise Module for Development Tools 15 SP7 | Affected |
| SUSE Linux Enterprise Module for Development Tools 15 SP7 | Affected |
| SUSE Linux Enterprise Module for Legacy 15 SP7 | Affected |
| SUSE Linux Enterprise Module for Legacy 15 SP7 | Affected |
| SUSE Linux Enterprise Module for Public Cloud 15 SP7 | Affected |
| SUSE Linux Enterprise Module for Public Cloud 15 SP7 | Affected |
| SUSE Linux Enterprise Real Time 15 SP7 | Affected |
| SUSE Linux Enterprise Server 15 SP7 | Affected |
| SUSE Linux Enterprise Server 15 SP7 | Affected |
| SUSE Linux Enterprise Server 16.0 | Affected |
| SUSE Linux Enterprise Server 16.0 | Affected |
| SUSE Linux Enterprise Server 16.1 | Affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP7 | Affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP7 | Affected |
| SUSE Linux Enterprise Server for SAP applications 16.0 | Affected |
| SUSE Linux Enterprise Server for SAP applications 16.0 | Affected |
| SUSE Linux Enterprise Server for SAP applications 16.1 | Affected |
| SUSE Linux Enterprise Workstation Extension 15 SP7 | Affected |
| SUSE Linux Enterprise Workstation Extension 15 SP7 | Affected |
| SUSE Linux Micro 6.0 | Affected |
| SUSE Linux Micro 6.0 | Affected |
| SUSE Linux Micro 6.0 | Affected |
| SUSE Linux Micro 6.1 | Affected |
| SUSE Linux Micro 6.1 | Affected |
| SUSE Linux Micro 6.1 | Affected |
| SUSE Linux Micro 6.2 | Affected |
| SUSE Linux Micro 6.2 | Affected |
| SUSE Real Time Module 15 SP7 | Affected |
| openSUSE Leap 16.0 | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP4 | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP4-LTSS | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP4-LTSS | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP5 | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP5-LTSS | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP5-LTSS | Affected |
| SUSE Linux Enterprise Live Patching 12 SP5 | Affected |
| SUSE Linux Enterprise Live Patching 12 SP5 | Affected |
| SUSE Linux Enterprise Live Patching 15 SP4 | Affected |
| SUSE Linux Enterprise Live Patching 15 SP4 | Affected |
| SUSE Linux Enterprise Live Patching 15 SP5 | Affected |
| SUSE Linux Enterprise Live Patching 15 SP5 | Affected |
| SUSE Linux Enterprise Module for Basesystem 15 SP4 | Affected |
| SUSE Linux Enterprise Module for Basesystem 15 SP5 | Affected |
| SUSE Linux Enterprise Module for Basesystem 15 SP6 | Affected |
| SUSE Linux Enterprise Module for Development Tools 15 SP4 | Affected |
| SUSE Linux Enterprise Module for Development Tools 15 SP5 | Affected |
| SUSE Linux Enterprise Module for Development Tools 15 SP6 | Affected |
| SUSE Linux Enterprise Server 11 SP4 LTSS EXTREME CORE | Not-Affected |
| SUSE Linux Enterprise Server 11 SP4 LTSS EXTREME CORE | Not-Affected |
| SUSE Linux Enterprise Server 12 SP5 | Affected |
| SUSE Linux Enterprise Server 12 SP5-LTSS | Affected |
| SUSE Linux Enterprise Server 12 SP5-LTSS | Affected |
| SUSE Linux Enterprise Server 12 SP5-LTSS Extended Security | Affected |
| SUSE Linux Enterprise Server 12 SP5-LTSS Extended Security | Affected |
| SUSE Linux Enterprise Server 15 SP4 | Affected |
| SUSE Linux Enterprise Server 15 SP4-LTSS | Affected |
| SUSE Linux Enterprise Server 15 SP4-LTSS | Affected |
| SUSE Linux Enterprise Server 15 SP5 | Affected |
| SUSE Linux Enterprise Server 15 SP5-LTSS | Affected |
| SUSE Linux Enterprise Server 15 SP5-LTSS | Affected |
| SUSE Linux Enterprise Server 15 SP6 | Affected |
| SUSE Linux Enterprise Server 15 SP6-LTSS | Affected |
| SUSE Linux Enterprise Server 15 SP6-LTSS | Affected |
| SUSE Linux Enterprise Server LTSS Extended Security 12 SP5 | Affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP6 | Affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP6 | Affected |
| SUSE Manager Proxy 4.3 | Affected |
| SUSE Manager Proxy LTS 4.3 | Affected |
| SUSE Manager Retail Branch Server 4.3 | Affected |
| SUSE Manager Retail Branch Server LTS 4.3 | Affected |
| SUSE Manager Server 4.3 | Affected |
| SUSE Manager Server LTS 4.3 | Affected |
| SUSE CaaS Platform 4.0 | Affected |
| SUSE Enterprise Storage 6 | Affected |
| SUSE Enterprise Storage 7 | Affected |
| SUSE Enterprise Storage 7.1 | Affected |
| SUSE Linux Enterprise Desktop 11 SP4 | Not-Affected |
| SUSE Linux Enterprise Desktop 12 SP4 | Not-Affected |
| SUSE Linux Enterprise Desktop 15 SP1 | Affected |
| SUSE Linux Enterprise Desktop 15 SP2 | Affected |
| SUSE Linux Enterprise Desktop 15 SP3 | Affected |
| SUSE Linux Enterprise Desktop 15 SP4 | Affected |
| SUSE Linux Enterprise Desktop 15 SP5 | Affected |
| SUSE Linux Enterprise Desktop 15 SP6 | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP1 | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP1-ESPOS | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP1-LTSS | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP2 | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP2-ESPOS | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP2-LTSS | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP3 | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP3-ESPOS | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP3-LTSS | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP4-ESPOS | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP5-ESPOS | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP6 | Affected |
| SUSE Linux Enterprise Micro 5.0 | Affected |
| SUSE Linux Enterprise Micro 5.1 | Affected |
| SUSE Linux Enterprise Micro 5.2 | Affected |
| SUSE Linux Enterprise Micro 5.2 | Affected |
| SUSE Linux Enterprise Module for Basesystem 15 SP1 | Affected |
| SUSE Linux Enterprise Module for Basesystem 15 SP2 | Affected |
| SUSE Linux Enterprise Module for Basesystem 15 SP3 | Affected |
| SUSE Linux Enterprise Module for Development Tools 15 SP1 | Affected |
| SUSE Linux Enterprise Module for Development Tools 15 SP2 | Affected |
| SUSE Linux Enterprise Module for Development Tools 15 SP3 | Affected |
| SUSE Linux Enterprise Real Time 15 SP2 | Affected |
| SUSE Linux Enterprise Real Time 15 SP3 | Affected |
| SUSE Linux Enterprise Real Time 15 SP4 | Affected |
| SUSE Linux Enterprise Real Time 15 SP4 | Affected |
| SUSE Linux Enterprise Real Time 15 SP5 | Affected |
| SUSE Linux Enterprise Server 11 SP4 | Not-Affected |
| SUSE Linux Enterprise Server 11 SP4-LTSS | Not-Affected |
| SUSE Linux Enterprise Server 12 SP4 | Not-Affected |
| SUSE Linux Enterprise Server 12 SP4-ESPOS | Not-Affected |
| SUSE Linux Enterprise Server 12 SP4-LTSS | Not-Affected |
| SUSE Linux Enterprise Server 12 SP4-LTSS | Not-Affected |
| SUSE Linux Enterprise Server 15 SP1 | Affected |
| SUSE Linux Enterprise Server 15 SP1-BCL | Affected |
| SUSE Linux Enterprise Server 15 SP1-LTSS | Affected |
| SUSE Linux Enterprise Server 15 SP1-LTSS | Affected |
| SUSE Linux Enterprise Server 15 SP2 | Affected |
| SUSE Linux Enterprise Server 15 SP2-BCL | Affected |
| SUSE Linux Enterprise Server 15 SP2-LTSS | Affected |
| SUSE Linux Enterprise Server 15 SP2-LTSS | Affected |
| SUSE Linux Enterprise Server 15 SP3 | Affected |
| SUSE Linux Enterprise Server 15 SP3-BCL | Affected |
| SUSE Linux Enterprise Server 15 SP3-LTSS | Affected |
| SUSE Linux Enterprise Server 15 SP3-LTSS | Affected |
| SUSE Linux Enterprise Server for SAP Applications 12 SP4 | Not-Affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP1 | Affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP2 | Affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP3 | Affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP4 | Affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP4 | Affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP5 | Affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP5 | Affected |
| SUSE Manager Proxy 4.0 | Affected |
| SUSE Manager Proxy 4.1 | Affected |
| SUSE Manager Proxy 4.2 | Affected |
| SUSE Manager Retail Branch Server 4.0 | Affected |
| SUSE Manager Retail Branch Server 4.1 | Affected |
| SUSE Manager Retail Branch Server 4.2 | Affected |
| SUSE Manager Server 4.0 | Affected |
| SUSE Manager Server 4.1 | Affected |
| SUSE Manager Server 4.2 | Affected |
| SUSE OpenStack Cloud 9 | Not-Affected |
| SUSE OpenStack Cloud Crowbar 9 | Not-Affected |
| SUSE Real Time Module 15 SP4 | Affected |
| SUSE Real Time Module 15 SP5 | Affected |
| openSUSE Leap 15.3 | Affected |
| openSUSE Leap 15.4 | Affected |
| openSUSE Leap 15.4 | Affected |
| openSUSE Leap 15.5 | Affected |
| openSUSE Leap 15.5 | Affected |
| openSUSE Leap 15.6 | Affected |
Share
External POC / Exploit Code
Leaving vuln.today
EUVD-2026-38852
GHSA-29w2-r4qv-vcrw