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Review reviewHigh

CVE-2026-23204

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: cls_u32: use skb_header_pointer_careful() skb_header_pointer() does not fully validate negative @offset values. Use skb_header_pointer_careful() instead. GangMin Kim provided a report and a repro fooling u32_classify(): BUG: KASAN: slab-out-of-bounds in u32_classify+0x1180/0x11b0 net/sched/cls_u32.c:221

CVSS
7.1
EPSS
0.12%
2.37% percentile
CISA KEV
Not listed
Published
2026.02.15
PRIORITY ASSESSMENT

Review review

The CVSS severity warrants an early asset and exposure review.

Known exploitationNot established by KEV
Exploit probability0.12%
Technical severityCVSS 7.1

Vulnerability overview

In the Linux kernel, the following vulnerability has been resolved: net/sched: cls_u32: use skb_header_pointer_careful() skb_header_pointer() does not fully validate negative @offset values. Use skb_header_pointer_careful() instead. GangMin Kim provided a report and a repro fooling u32_classify(): BUG: KASAN: slab-out-of-bounds in u32_classify+0x1180/0x11b0 net/sched/cls_u32.c:221

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
>= fbc2e7d9cf49e0bf89b9e91fd60a06851a855c5d < 66e4b63d61c15de6ca5332d9ca6db59a404d7136, >= fbc2e7d9cf49e0bf89b9e91fd60a06851a855c5d < 29681ed51e737be14d18ecd1c304c57002e4b72c, >= fbc2e7d9cf49e0bf89b9e91fd60a06851a855c5d < cfa745830e45ecb75c061aa34330ee0cac941cc7, >= fbc2e7d9cf49e0bf89b9e91fd60a06851a855c5d < 13336a6239b9d7c6e61483017bb8bdfe3ceb10a5, >= fbc2e7d9cf49e0bf89b9e91fd60a06851a855c5d < e41a23e61259f5526af875c3b86b3d42a9bae0e5, >= fbc2e7d9cf49e0bf89b9e91fd60a06851a855c5d < 8a672f177ebe19c93d795fbe967846084fbc7943, >= fbc2e7d9cf49e0bf89b9e91fd60a06851a855c5d < cabd1a976375780dabab888784e356f574bbaed8, >= 2.6.35, >= V3.1.6, >= V3.1.5, >= 2.6.35.1 < 6.6.124, >= 6.7 < 6.12.70, >= 6.13 < 6.18.10, 2.6.35, 6.19
Fixed versions
6.6.124, 6.12.70, 6.18.10

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:N/A:H
CWE
CWE-125