dbcve.org
Linux KernelOperating system · Linux

CVE-2026-52984

MEDIUM · 5.5 CVSS v3.1 Published 2026-06-24
Fix available
A fix is available. Upgrade to 5.5 / 5.10.258 or later.
See remediation →
57/100
Remediation priority · Elevated
Zero-click Patch available 8 weeks old

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
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.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

The netem qdisc in the Linux kernel fails to properly enforce its queue limit (sch->limit) when packet reordering is enabled. The limit check only counts packets in the internal tfifo queue (q->t_len) but ignores packets placed directly into the underlying sch->q by the reorder path (__qdisc_enqueue_head), allowing total queue occupancy to exceed the configured limit under reordering conditions.

MitigationUntil the kernel is updated with the fix, limit concurrent queued packets or reduce delay/ordering settings to stay below default limits; the proper fix requires updating the Linux kernel to include sch->q.qlen in the netem queue limit check.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Linux KernelOperating system
Affected:>= 5.4.288, < 5.5>= 5.10.232, < 5.10.258>= 5.15.175, < 5.15.209>= 6.1.121, < 6.1.175>= 6.6.67, < 6.6.141>= 6.12.6, < 6.12.91>= 6.13.1, < 6.18.33>= 6.19, < 7.0.10= 6.13= 7.1

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Local
Complexity
Low
Privileges
Low
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Check kernel version
    Run `uname -r` to get the running kernel version
    Affected if The kernel version falls within any of these ranges: >= 5.4.288 and < 5.5; >= 5.10.232 and < 5.10.258; >= 5.15.175 and < 5.15.209; >= 6.1.121 and < 6.1.175; >= 6.6.67 and < 6.6.141; >= 6.12.6 and < 6.12.91; >= 6.13.1 and < 6.18.33; >= 6.19 and < 7.0.10; or equals 6.13 or 7.1
  2. Identify netem qdisc in use
    Run `tc qdisc show` and look for entries with 'netem' in the qdisc column
    Affected if No netem qdisc is configured on any interface (the vulnerability only applies when netem is actively used)
  3. Verify netem reordering is enabled
    Run `tc qdisc show` and inspect the netem parameters; look for 'reorder' or 'delay' with variation settings that trigger reordering behavior
    Affected if The netem configuration does not have reordering enabled (the flaw only manifests when packet reordering is configured)
  4. Check netem limit configuration
    Run `tc qdisc show` and look for the 'limit' parameter on netem qdiscs; if not explicitly set, the default is 1000 packets
    Affected if A netem qdisc is configured with an explicit limit value (the vulnerability allows queue to exceed this limit under reordering conditions)

A system is affected if it runs a kernel version in the affected ranges AND has a netem qdisc configured with reordering enabled and a non-default limit, because the queue can exceed the configured limit under reordering conditions.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 5.5 / 5.10.258 / 5.15.209 or later
Fixed in 5.55.10.2585.15.209
Vendor patch git.kernel.org →
Interim mitigation

Until the kernel is updated with the fix, limit concurrent queued packets or reduce delay/ordering settings to stay below default limits; the proper fix requires updating the Linux kernel to include sch->q.qlen in the netem queue limit check.

Recommended fix High confidence

Upgrade to kernel 5.5+ (5.4.x branch), 5.10.258+ (5.10.x branch), 5.15.209+ (5.15.x branch), or 6.1.175+ (6.1.x branch)

  1. Identify the currently running Linux kernel version using `uname -r`
  2. Determine which kernel branch (5.4.x, 5.10.x, 5.15.x, or 6.1.x) your system is using
  3. Upgrade the Linux kernel to the fixed version for your branch: 5.5 or later for 5.4.x, 5.10.258 or later for 5.10.x, 5.15.209 or later for 5.15.x, or 6.1.175 or later for 6.1.x
  4. For distribution-based systems, use the package manager to install the updated kernel (e.g., `apt-get update && apt-get install linux-image-<version>` for Debian/Ubuntu, or `yum update kernel` for RHEL/CentOS)
  5. Reboot the system to load the new kernel
  6. Verify the fix is applied by checking the kernel version matches or exceeds the fixed release
Caveat Kernel upgrades may require driver recompilation and a system reboot; ensure compatibility with custom modules or specialized hardware before upgrading

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Linux Kernel Scoped from the published advisory
  • Consultation2.0 h
  • Implementation1.0 h
  • Testing4.0 h
  • Review / QA2.0 h
9.0 hours of engineering $1,540
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,464.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2026-52984 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

Get it on GitHub Scan in the browser

References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-52984 in production — separate from our analysis above.

No notes yet

Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.

What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data