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Review reviewHigh

CVE-2026-23340

Linux Linux, SIMATIC S7-1500 CPU 1518-4 PN/DP MFP, SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP

In the Linux kernel, the following vulnerability has been resolved: net: sched: avoid qdisc_reset_all_tx_gt() vs dequeue race for lockless qdiscs When shrinking the number of real tx queues, netif_set_real_num_tx_queues() calls qdisc_reset_all_tx_gt() to flush qdiscs for queues which will no longer be used. qdisc_reset_all_tx_gt() currently serializes qdisc_reset() with qdisc_lock(). However, for lockless qdiscs, the dequeue path is serialized by qdisc_run_begin/end() using qdisc->seqlock instead, so qdisc_reset() can run concurrently with __qdisc_run() and free skbs while they are still be...

CVSS
7.8
EPSS
0.14%
3.57% percentile
CISA KEV
Not listed
Published
2026.03.25
PRIORITY ASSESSMENT

Review review

The CVSS severity warrants an early asset and exposure review.

Known exploitationNot established by KEV
Exploit probability0.14%
Technical severityCVSS 7.8

Vulnerability overview

In the Linux kernel, the following vulnerability has been resolved: net: sched: avoid qdisc_reset_all_tx_gt() vs dequeue race for lockless qdiscs When shrinking the number of real tx queues, netif_set_real_num_tx_queues() calls qdisc_reset_all_tx_gt() to flush qdiscs for queues which will no longer be used. qdisc_reset_all_tx_gt() currently serializes qdisc_reset() with qdisc_lock(). However, for lockless qdiscs, the dequeue path is serialized by qdisc_run_begin/end() using qdisc->seqlock instead, so qdisc_reset() can run concurrently with __qdisc_run() and free skbs while they are still be...

Affected product and versions

Product
Linux Linux, SIMATIC S7-1500 CPU 1518-4 PN/DP MFP, SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP
Affected versions
>= 6b3ba9146fe64b9bebb6346c9dcfe3b4851de2d7 < 5bb27ad54d12de67e457d7d251198e361bef835e, >= 6b3ba9146fe64b9bebb6346c9dcfe3b4851de2d7 < 7594467c49bfc2f4644dee0415ac2290db11fa0d, >= 6b3ba9146fe64b9bebb6346c9dcfe3b4851de2d7 < dbd58b0730aa06ab6ad26079cf9a5b6b58e7e750, >= 6b3ba9146fe64b9bebb6346c9dcfe3b4851de2d7 < 5bc4e69306ed7ae02232eb4c0b23ed621a26d504, >= 6b3ba9146fe64b9bebb6346c9dcfe3b4851de2d7 < 8314944cc3bdeaa5a73e6f8a8cf0d94822e625cb, >= 6b3ba9146fe64b9bebb6346c9dcfe3b4851de2d7 < c69df4e0524f8de8e176ba389acd83e85f5f49d0, >= 6b3ba9146fe64b9bebb6346c9dcfe3b4851de2d7 < 7f083faf59d14c04e01ec05a7507f036c965acf8, >= 4.16, >= V3.1.6, >= V3.1.5, >= 4.16.1 < 5.15.203, >= 5.16 < 6.1.167, >= 6.2 < 6.6.130, >= 6.7 < 6.12.77, >= 6.13 < 6.18.17, >= 6.19 < 6.19.7, 4.16, 7.0
Fixed versions
5.15.203, 6.1.167, 6.6.130, 6.12.77, 6.18.17, 6.19.7

Recommended response sequence

Confirm exposure before applying a vendor-supported change.

Full remediation guide
  1. 1
    Identify

    Confirm that Linux Linux, SIMATIC S7-1500 CPU 1518-4 PN/DP MFP, SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP and an affected version are present.

  2. 2
    Prioritize

    Combine exploitation signals with asset exposure and business criticality.

  3. 3
    Remediate

    Follow the vendor advisory or supported update path and preserve rollback options.

  4. 4
    Verify

    Recheck the version, service health, access paths, and relevant logs.

Technical data

CVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CWE
CWE-416