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NVD / CVE Program· CNA Linux

CVE-2026-98017: net/sched: defer qdisc freeing after failed creation

Noroxi assessment

Priority: Monitor (action score 31/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.12% (FIRST EPSS).
  • Someone with local access to the system can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
  • Fixed version: Linux Linux 156a3bab69744e9225bb9eff8c5cc53da18d5a2e, 20bf6fa34b345333971bd4464a322cce87b83f4e, 5bfe927c5b4b290fad529186218c728589b4b101; azl3 kernel 6.6.157.1-1 on Azure Linux 3.0 6.6.158.1-1.
  • Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Upgrade to Linux Linux 156a3bab69744e9225bb9eff8c5cc53da18d5a2e, 20bf6fa34b345333971bd4464a322cce87b83f4e, 5bfe927c5b4b290fad529186218c728589b4b101; azl3 kernel 6.6.157.1-1 on Azure Linux 3.0 6.6.158.1-1 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

In the Linux kernel, the following vulnerability has been resolved: net/sched: defer qdisc freeing after failed creation An RTM_NEWQDISC request can make clsact bind a populated shared ingress block during ->init(), publishing an embedded mini_Qdisc to lockless readers. If the same request has an invalid TCA_RATE, estimator setup fails after ->init(); the unwind removes the pointer but synchronously frees its containing qdisc while tc_run() may still hold it. Retire failed qdiscs through the same RCU helper as normal destruction. Inline the synchronous free into the callback now that no direct callers remain.

HighCVSS 7.8 · v3.1—No exploit Fix available
Published
Sep 25, 2026
Updated
Oct 19, 2026
EPSS
0.1% · 2th percentile
CWE
—

Report tools

JSON

Action score

31

Monitor

Low priority for now.

CVSS
31 / 40 · 7.8 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.1%

CNA vs NVD score

NVD
—
CNA · Linux
7.8
NVD has not scored this yet; the score shown is the CNA’s.

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

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When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

—

Versions reported by the vendor

Affected version ranges reported by the assigning authority (Linux). Independent of NVD's CPE analysis and usually ahead of it.

  • Linux Linux

    • 4.16affected
    • 51ab2994c387c80b45caf8b8067b3f3b97771d25 and later · before 96a27a3e64e7c87abade03fb2ad04ed66992a89aaffected · git
    • 51ab2994c387c80b45caf8b8067b3f3b97771d25 and later · before 6a1b49bb9fdf9e8e7aa38e8cd635c0cc4074447daffected · git
    • 51ab2994c387c80b45caf8b8067b3f3b97771d25 and later · before 20bf6fa34b345333971bd4464a322cce87b83f4eaffected · git
    • 51ab2994c387c80b45caf8b8067b3f3b97771d25 and later · before 156a3bab69744e9225bb9eff8c5cc53da18d5a2eaffected · git
    • 51ab2994c387c80b45caf8b8067b3f3b97771d25 and later · before 5bfe927c5b4b290fad529186218c728589b4b101affected · git
    • 51ab2994c387c80b45caf8b8067b3f3b97771d25 and later · before e6662f2100f8d33b0f4d0047c219efd6bba186eaaffected · git
    • before 4.16not affected · semver
    • 6.1.189 and later · up to and including 6.1.*not affected · semver
    • 6.6.158 and later · up to and including 6.6.*not affected · semver

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Debian:12linuxbefore 6.1.190-16.1.190-1
Debian:12linux-6.12before 6.12.111-1~deb12u16.12.111-1~deb12u1
Debian:13linuxbefore 6.12.111-16.12.111-1
Debian:14linuxbefore 7.2.7-17.2.7-1

Same product

linux: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-74705udp: fix potential use-after-free in tunnel segmentation
    40Plan
  • CVE-2026-74612veth: fix skb length accounting after XDP frag adjustment
    40Plan
  • CVE-2026-74475vxlan: use neigh_ha_snapshot() in route_shortcircuit()
    40Plan

Published before and after this one in the same product

  • ← EarlierCVE-2026-98015Sep 25, 2026 · net/mlx5: E-Switch: fix use-after-free in mlx5_eswitch_termtbl_put
    0Monitor
  • ← EarlierCVE-2026-98016Sep 25, 2026 · net/mlx5e: Fix use-after-free race in sample_restore_put()
    0Monitor
  • Later →CVE-2026-98018Sep 25, 2026 · net: mctp: i3c: serialize probe with bus removal
    0Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
Linux Linux156a3bab69744e9225bb9eff8c5cc53da18d5a2eVendor (CNA)
Linux Linux20bf6fa34b345333971bd4464a322cce87b83f4eVendor (CNA)
Linux Linux5bfe927c5b4b290fad529186218c728589b4b101Vendor (CNA)
Linux Linux6a1b49bb9fdf9e8e7aa38e8cd635c0cc4074447dVendor (CNA)
Linux Linux96a27a3e64e7c87abade03fb2ad04ed66992a89aVendor (CNA)
Linux Linuxe6662f2100f8d33b0f4d0047c219efd6bba186eaVendor (CNA)
azl3 kernel 6.6.157.1-1 on Azure Linux 3.06.6.158.1-1 · Release NotesMicrosoft (MSRC)
debian:linux6.1.190-1 · Debian:12Package registry (OSV)
debian:linux6.12.111-1 · Debian:13Package registry (OSV)
debian:linux-6.126.12.111-1~deb12u1 · Debian:12Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

National notice (Türkiye Cybersecurity Directorate / USOM)

Official security notices citing this record; remediation advice is on the agency's page.

All national notices →

Technical details

Attack conditions

  • Someone with local access to the system can trigger it.
  • A low-privileged account is enough.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
high · data can be read
Integrity
high · data or configuration can be modified
Availability
high · the service can be disrupted
Attack vector
Local
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality impact
High
Integrity impact
High
Availability impact
High

Weakness class (CWE)

—

CVSS vector

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

nvd-secondary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

  1. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (5 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records