Unknown

CVE-2026-97959 — net/sched: cls_route: free emptied bucket on filter move

In the Linux kernel, the following vulnerability has been resolved: net/sched: cls_route: free emptied bucket on filter move route4_change can move an existing filter to a different top-level bucket: route4_set_parms recomputes the handle from TCA_ROUTE4_TO/ FROM/IIF, and the handle-mismatch check is gated on the 'new' flag, so for an existing filter the new handle may differ from the old one and land in a different bucket. When this happens, the filter is unlinked from the old bucket, but the bucket itself is never freed once it goes empty. The stale empty bucket remains in head->table[], causing route4_delete to report *last=false even after the last live filter is gone. That pins the empty tcf_proto and causes a leak. Fix this by refcounting the filters linked to a bucket and freeing the bucket when the count drops to zero. The existing scan in route4_delete goes away with it. The count is updated at all sites that link or unlink a filter during add, change and delete, and the bucket is dropped from head->table[] as soon as it reaches zero. Conditions to recreate the bug: CONFIG_NET_CLS_ROUTE4=y, CONFIG_NET_SCH_INGRESS=y, CONFIG_NET_CLS_ACT=y. tc qdisc replace dev lo clsact tc filter add dev lo ingress protocol ip pref 100 route from 1 to 1 tc filter change dev lo ingress protocol ip pref 100 handle 0x10001 \ route from 1 to 2 tc filter del dev lo ingress protocol ip pref 100 handle 0x10002 \ route from 1 to 2 tc filter show dev lo ingress | grep -c 'pref 100 route chain 0 '

Published Sep 25, 2026 · Updated Oct 16, 2026 · Sources: NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP · CNA: Linux

Low

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

No exploitation signal in the sources consulted so far.

How the score was calculated

EPSS 0.2% (30-day exploitation probability)+1

The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.

Exploitation

Not confirmed

Not in CISA KEV — an absence of record, not proof it is unexploited.

EPSS FIRST

0.18%

ahead of 7% of scored CVEs · Oct 16, 2026

Affects

Linux

CVSS base

—

Score not published yet.

Remediation

Fixes and mitigations documented by the sources — linked to the original advisory.

No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.

First 24 hours

Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.

Identify exposed assets running the affected vendor/product/version combinations (Linux Linux).
No fix documented in the sources: reduce exposure and monitor the vendor advisory.
Search available logs for exploit probes, errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

Vendor	Product	Versions	Status	Source
Linux	Linux	≥ 1e052be69d045c8d0f82ff1116fd3e5a79661745 and < 9e7741b41a25b9d49df4d262fa314342e6f95c50≥ 1e052be69d045c8d0f82ff1116fd3e5a79661745 and < 48d38bf8c22a05fde07ba1f885cde27b851649a2≥ 1e052be69d045c8d0f82ff1116fd3e5a79661745 and < cc99d26b12431e4e4d0e346ec32764eb42c0aed9≥ 1e052be69d045c8d0f82ff1116fd3e5a79661745 and < 41e94079200aaf0cdbe4594b0af75710b33da124≥ 1e052be69d045c8d0f82ff1116fd3e5a79661745 and < 2e2f130951d34871b0643bf700164d97cff4b427≥ 1e052be69d045c8d0f82ff1116fd3e5a79661745 and < f8495d67434e1cb7e511297687ca55fdb28e4c20≥ 1e052be69d045c8d0f82ff1116fd3e5a79661745 and < 81dd117c04422c6d0c7974aba9fa6a0ba370959b≥ 1e052be69d045c8d0f82ff1116fd3e5a79661745 and < 1853f30cf5c84971f99788a76207c6f745380896 and 1 more version 4.1	Vulnerable	CVE Program (cve.org) e CISA ADP

EPSS over time FIRST

Oct 15, 2026 → Oct 16, 2026 · 2 reading(s) · max 0.18%

Detection

Read off the CVSS vector and the weakness class. Starting points, not tested rules.

Not enough vector or weakness data: use the affected application’s logs as a starting point.

application logs

Timeline

What happened to this CVE, newest first.

2026
Record published
Oct 16, 2026
Affected products added · linux/linux
Oct 16, 2026 · CVE Program (cve.org) e CISA ADP
Source status changed · → Received
Oct 15, 2026 · NIST National Vulnerability Database
Record created in this database
Oct 15, 2026 · NIST National Vulnerability Database
CVE published
Sep 25, 2026 · Linux

Source activity

Repeated readings are counted rather than listed.

1× Official description updated · Oct 15, 2026 – Oct 15, 2026

References

8 on the record

git.kernel.org/stable/c/f8495d67434e1cb7e511297687ca55fdb28e4c20
NIST National Vulnerability Database
git.kernel.org/stable/c/1853f30cf5c84971f99788a76207c6f745380896
NIST National Vulnerability Database
git.kernel.org/stable/c/41e94079200aaf0cdbe4594b0af75710b33da124
NIST National Vulnerability Database
git.kernel.org/stable/c/2e2f130951d34871b0643bf700164d97cff4b427
NIST National Vulnerability Database
git.kernel.org/stable/c/9e7741b41a25b9d49df4d262fa314342e6f95c50
NIST National Vulnerability Database
git.kernel.org/stable/c/81dd117c04422c6d0c7974aba9fa6a0ba370959b
NIST National Vulnerability Database
git.kernel.org/stable/c/cc99d26b12431e4e4d0e346ec32764eb42c0aed9
NIST National Vulnerability Database
git.kernel.org/stable/c/48d38bf8c22a05fde07ba1f885cde27b851649a2
NIST National Vulnerability Database

Elsewhere on this site

Linux
every CVE for this vendor

Related CVEs (same products)

Critical CVE-2026-99999 ipv4: validate checksum_start before completing checksum 1d
Unknown CVE-2026-98432 ipv4: free inet_opt and ireq_opt after an RCU grace period 1d
Unknown CVE-2026-98430 RDMA/efa: Keep admin queues alive while IRQ is registered 2d
Unknown CVE-2026-98424 wifi: cfg80211: undo netns switch if renaming the wiphy fails 2d
Unknown CVE-2026-98425 wifi: mac80211: don't warn when an IBSS has no channel to scan 2d
Unknown CVE-2026-98426 wifi: mwifiex: fix IRQ leak using wrong index in MSI-X error path 2d

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

No CVSS score published by NVD, the CNA, CISA or GitHub so far.
No fixed version, patch or mitigation documented.
No CISA SSVC assessment.
No CWE classification.
No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record

Text assembled only from the fields above — no additional claims.

What should defenders know first?

CVE-2026-97959 is "net/sched: cls_route: free emptied bucket on filter move", rated Unknown. It affects Linux (Linux); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. EPSS 0.18% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.

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