NVD / CVE Program· CNA Linux

CVE-2025-68815: net/sched: ets: Remove drr class from the active list if it changes to strict

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: 0.15% (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 02783a37cb1c0a2bd9fcba4ff1b81e6e209c7d87, 2f125ebe47d6369e562f3cbd9b6227cff51eaf34, 43d9a530c8c094d137159784e7c951c65f11ec6c; azl3 kernel 6.6.119.3-3 on Azure Linux 3.0 6.6.121.1-1.

Low priority for now. Upgrade to Linux Linux 02783a37cb1c0a2bd9fcba4ff1b81e6e209c7d87, 2f125ebe47d6369e562f3cbd9b6227cff51eaf34, 43d9a530c8c094d137159784e7c951c65f11ec6c; azl3 kernel 6.6.119.3-3 on Azure Linux 3.0 6.6.121.1-1 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: ets: Remove drr class from the active list if it changes to strict Whenever a user issues an ets qdisc change command, transforming a drr class into a strict one, the ets code isn't checking whether that class was in the active list and removing it. This means that, if a user changes a strict class (which was in the active list) back to a drr one, that class will be added twice to the active list [1]. Doing so with the following commands: tc qdisc add dev lo root handle 1: ets bands 2 strict 1 tc qdisc add dev lo parent 1:2 handle 20: \ tbf rate 8bit burst 100b latency 1s tc filter add dev lo parent 1: basic classid 1:2 ping -c1 -W0.01 -s 56 127.0.0.1 tc qdisc change dev lo root handle 1: ets bands 2 strict 2 tc qdisc change dev lo root handle 1: ets bands 2 strict 1 ping -c1 -W0.01 -s 56 127.0.0.1 Will trigger the following splat with list debug turned on: [ 59.279014][ T365] ------------[ cut here ]------------ [ 59.279452][ T365] list_add double add: new=ffff88801d60e350, prev=ffff88801d60e350, next=ffff88801d60e2c0. [ 59.280153][ T365] WARNING: CPU: 3 PID: 365 at lib/list_debug.c:35 __list_add_valid_or_report+0x17f/0x220 [ 59.280860][ T365] Modules linked in: [ 59.281165][ T365] CPU: 3 UID: 0 PID: 365 Comm: tc Not tainted 6.18.0-rc7-00105-g7e9f13163c13-dirty #239 PREEMPT(voluntary) [ 59.281977][ T365] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 [ 59.282391][ T365] RIP: 0010:__list_add_valid_or_report+0x17f/0x220 [ 59.282842][ T365] Code: 89 c6 e8 d4 b7 0d ff 90 0f 0b 90 90 31 c0 e9 31 ff ff ff 90 48 c7 c7 e0 a0 22 9f 48 89 f2 48 89 c1 4c 89 c6 e8 b2 b7 0d ff 90 <0f> 0b 90 90 31 c0 e9 0f ff ff ff 48 89 f7 48 89 44 24 10 4c 89 44 ... [ 59.288812][ T365] Call Trace: [ 59.289056][ T365] <TASK> [ 59.289224][ T365] ? srso_alias_return_thunk+0x5/0xfbef5 [ 59.289546][ T365] ets_qdisc_change+0xd2b/0x1e80 [ 59.289891][ T365] ? __lock_acquire+0x7e7/0x1be0 [ 59.290223][ T365] ? __pfx_ets_qdisc_change+0x10/0x10 [ 59.290546][ T365] ? srso_alias_return_thunk+0x5/0xfbef5 [ 59.290898][ T365] ? __mutex_trylock_common+0xda/0x240 [ 59.291228][ T365] ? __pfx___mutex_trylock_common+0x10/0x10 [ 59.291655][ T365] ? srso_alias_return_thunk+0x5/0xfbef5 [ 59.291993][ T365] ? srso_alias_return_thunk+0x5/0xfbef5 [ 59.292313][ T365] ? trace_contention_end+0xc8/0x110 [ 59.292656][ T365] ? srso_alias_return_thunk+0x5/0xfbef5 [ 59.293022][ T365] ? srso_alias_return_thunk+0x5/0xfbef5 [ 59.293351][ T365] tc_modify_qdisc+0x63a/0x1cf0 Fix this by always checking and removing an ets class from the active list when changing it to strict. [1] https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net.git/tree/net/sched/sch_ets.c?id=ce052b9402e461a9aded599f5b47e76bc727f7de#n663

HighCVSS 7.8 · v3.1—No exploit Fix available

Memory safety

BDU:2026-09423

Published: Jan 13, 2026
Updated: Oct 19, 2026
EPSS: 0.1% · 4th percentile
CWE: CWE-416

Report tools

JSON

Action score

Monitor

Low priority for now.

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

CISA SSVC decision

Exploitation: none
Automatable: no
Technical impact: total

Vulnrichment: CISA's decision-tree inputs.

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.

Running WordPress? Scan your site free with WP Lens

Is your version affected? Check it

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.

We use this product, ask for help

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
- d05330672afe2e142ba97e63bd7c1faef76781bb, 5.14affected
- f517335a61ff8037b18ba1b0a002c1f82926a934 and later · before 58fdce6bc005e964f1dbc3ca716f5fe0f68839a2affected · git
- cd9b50adc6bb9ad3f7d244590a389522215865c4 and later · before 02783a37cb1c0a2bd9fcba4ff1b81e6e209c7d87affected · git
- cd9b50adc6bb9ad3f7d244590a389522215865c4 and later · before 8067db5c95aab9461d23117679338cd8869831faaffected · git
- cd9b50adc6bb9ad3f7d244590a389522215865c4 and later · before 2f125ebe47d6369e562f3cbd9b6227cff51eaf34affected · git
- cd9b50adc6bb9ad3f7d244590a389522215865c4 and later · before cca2ed931b734fe48139bc6f020e47367346630faffected · git
- cd9b50adc6bb9ad3f7d244590a389522215865c4 and later · before 43d9a530c8c094d137159784e7c951c65f11ec6caffected · git
- cd9b50adc6bb9ad3f7d244590a389522215865c4 and later · before b1e125ae425aba9b45252e933ca8df52a843ec70affected · git
- 5.10.62 and later · before 5.10.248affected · semver
- 5.13.14 and later · before 5.14affected · semver

Package-level exposure

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

Ecosystem	Package	Affected range	Fix
Debian:12	linux	before 6.1.162-1	6.1.162-1
Debian:13	linux	before 6.12.69-1	6.12.69-1
Debian:14	linux	before 6.18.3-1	6.18.3-1

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-2025-68813Jan 13, 2026 · ipvs: fix ipv4 null-ptr-deref in route error path
0Monitor
← EarlierCVE-2025-68814Jan 13, 2026 · io_uring: fix filename leak in __io_openat_prep()
0Monitor
Later →CVE-2025-68816Jan 13, 2026 · net/mlx5: fw_tracer, Validate format string parameters
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 / package	Fixed version	Source
Linux Linux	02783a37cb1c0a2bd9fcba4ff1b81e6e209c7d87	Vendor (CNA)
Linux Linux	2f125ebe47d6369e562f3cbd9b6227cff51eaf34	Vendor (CNA)
Linux Linux	43d9a530c8c094d137159784e7c951c65f11ec6c	Vendor (CNA)
Linux Linux	5.10.248	Vendor (CNA)
Linux Linux	5.14	Vendor (CNA)
Linux Linux	58fdce6bc005e964f1dbc3ca716f5fe0f68839a2	Vendor (CNA)
Linux Linux	8067db5c95aab9461d23117679338cd8869831fa	Vendor (CNA)
Linux Linux	b1e125ae425aba9b45252e933ca8df52a843ec70	Vendor (CNA)
Linux Linux	cca2ed931b734fe48139bc6f020e47367346630f	Vendor (CNA)
azl3 kernel 6.6.119.3-3 on Azure Linux 3.0	6.6.121.1-1 · CBL-Mariner Releases	Microsoft (MSRC)
debian:linux	6.1.162-1 · Debian:12	Package 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.

No history yet (it accumulates with the daily EPSS job).

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.

CVE-2026-63979187 days apartnet/handshake: hand off the pinned file reference to accept_doit
39Monitor
CVE-2026-64523193 days apartnet/handshake: Take a long-lived file reference at submit
39Monitor
CVE-2026-64530194 days apartnet/sched: cls_api: Handle TC_ACT_CONSUMED in tcf_qevent_handle
39Monitor
CVE-2026-64541195 days apartnet/smc: fix UAF in smc_cdc_rx_handler() by pinning the socket
39Monitor
CVE-2026-64564203 days apartsctp: don't free the ASCONF's own transport in DEL-IP processing
39Monitor
CVE-2026-68156209 days apartlibceph: refresh auth->authorizer_buf{,_len} after authorizer update
39Monitor

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).

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)

CWE-416 · Use After Free

CVSS vector

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

nvd-secondary

Root cause

After a memory region is freed, another reference pointing to it is still used. By then, the same region may have been allocated for different data.

The bug in code

The whole CWE-416 class

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

1free(dev->buf);
2/* ... another thread is still running ... */
3process(dev->buf);

Fixed

1lock(&dev->lock);
2free(dev->buf);
3dev->buf = NULL;
4unlock(&dev->lock);

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

SSVC exploitation— → noneOct 16, 2026, 5:07 PM UTC
Fix✗ → ✓Sep 28, 2026, 10:11 PM UTC

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

References

git.kernel.org/stable/c/02783a37cb1c0a2bd9fcba4ff1b81e6e209c7d87

Show all references (6 more)

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

All records