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Review reviewHigh

CVE-2026-23449

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: teql: Fix double-free in teql_master_xmit Whenever a TEQL devices has a lockless Qdisc as root, qdisc_reset should be called using the seq_lock to avoid racing with the datapath. Failure to do so may cause crashes like the following: [ 238.028993][ T318] BUG: KASAN: double-free in skb_release_data (net/core/skbuff.c:1139) [ 238.029328][ T318] Free of addr ffff88810c67ec00 by task poc_teql_uaf_ke/318 [ 238.029749][ T318] [ 238.029900][ T318] CPU: 3 UID: 0 PID: 318 Comm: poc_teql_ke Not tainted 7.0.0-rc3-00149-ge5b...

CVSS
7.8
EPSS
0.13%
2.97% percentile
CISA KEV
Not listed
Published
2026.04.04
PRIORITY ASSESSMENT

Review review

The CVSS severity warrants an early asset and exposure review.

Known exploitationNot established by KEV
Exploit probability0.13%
Technical severityCVSS 7.8

Vulnerability overview

In the Linux kernel, the following vulnerability has been resolved: net/sched: teql: Fix double-free in teql_master_xmit Whenever a TEQL devices has a lockless Qdisc as root, qdisc_reset should be called using the seq_lock to avoid racing with the datapath. Failure to do so may cause crashes like the following: [ 238.028993][ T318] BUG: KASAN: double-free in skb_release_data (net/core/skbuff.c:1139) [ 238.029328][ T318] Free of addr ffff88810c67ec00 by task poc_teql_uaf_ke/318 [ 238.029749][ T318] [ 238.029900][ T318] CPU: 3 UID: 0 PID: 318 Comm: poc_teql_ke Not tainted 7.0.0-rc3-00149-ge5b...

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
>= 96009c7d500efdd5534e83b2e3eb2c58d4b137ae < 4e8ebc4c18ea8213d28e6cb867d18fcc67daca21, >= 96009c7d500efdd5534e83b2e3eb2c58d4b137ae < 21c89a0a8de7eadad8d385645a95b3233f23130e, >= 96009c7d500efdd5534e83b2e3eb2c58d4b137ae < afbc79a7770b230a9f24bd39271209d6b3682c5f, >= 96009c7d500efdd5534e83b2e3eb2c58d4b137ae < e9c66d3e7d8557b3308e55c613aa07254fe97611, >= 96009c7d500efdd5534e83b2e3eb2c58d4b137ae < 4a233447b941db451ea5f5a0942cffd0f7f7eaae, >= 96009c7d500efdd5534e83b2e3eb2c58d4b137ae < 66360460cab63c248ca5b1070a01c0c29133b960, >= 4.18, >= V3.1.6, >= V3.1.5, >= 4.18 < 6.1.167, >= 6.2 < 6.6.130, >= 6.7 < 6.12.78, >= 6.13 < 6.18.20, >= 6.19 < 6.19.10, 7.0
Fixed versions
6.1.167, 6.6.130, 6.12.78, 6.18.20, 6.19.10

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-415