High severity · published Feb 14, 2026
CVE-2026-23204
net/sched: cls_u32: use skb_header_pointer_careful()
7.1
CVSS
0.2%
EPSS
No
On KEV
Description
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 vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H
Attack vector
Local
Complexity
Low
Privileges
Low
User interaction
None
Confidentiality
High
Integrity
None
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.2% · higher than 4% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
KE
Kernel · Linux
2.6.35.1 before 6.6.124; 6.7 before 6.12.70; 6.13 before 6.18.10; 2.6.35; 2.6.35; 2.6.35; +11 more · source: NVD
LI
Linux · Linux
fbc2e7d9cf49e0bf89b9e91fd60a06851a855c5d before 66e4b63d61c15de6ca5332d9ca6db59a404d7136; fbc2e7d9cf49e0bf89b9e91fd60a06851a855c5d before 29681ed51e737be14d18ecd1c304c57002e4b72c; fbc2e7d9cf49e0bf89b9e91fd60a06851a855c5d before cfa745830e45ecb75c061aa34330ee0cac941cc7; fbc2e7d9cf49e0bf89b9e91fd60a06851a855c5d before 13336a6239b9d7c6e61483017bb8bdfe3ceb10a5; fbc2e7d9cf49e0bf89b9e91fd60a06851a855c5d before e41a23e61259f5526af875c3b86b3d42a9bae0e5; fbc2e7d9cf49e0bf89b9e91fd60a06851a855c5d before 8a672f177ebe19c93d795fbe967846084fbc7943; +2 more · source: vendor
SS
SIMATIC S7-1500 CPU 1518-4 PN/DP MFP · Siemens
V3.1.6; V3.1.5; V3.1.7; V3.1.6; V3.1.5; V3.1.7 · source: CISA
SS
SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP · Siemens
V3.1.6; V3.1.5; V3.1.7; V3.1.6; V3.1.5; V3.1.7 · source: CISA
SS
SIMATIC S7-1500 TM MFP - GNU/Linux subsystem · Siemens
0 · source: CISA
SS
SIPLUS S7-1500 CPU 1518-4 PN/DP MFP · Siemens
V3.1.6; V3.1.5; V3.1.7 · source: CISA
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-23204
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-23204
Patch
https://git.kernel.org/stable/c/13336a6239b9d7c6e61483017bb8bdfe3ceb10a5
git.kernel.org
https://git.kernel.org/stable/c/29681ed51e737be14d18ecd1c304c57002e4b72c
git.kernel.org
https://git.kernel.org/stable/c/66e4b63d61c15de6ca5332d9ca6db59a404d7136
Patch
https://git.kernel.org/stable/c/8a672f177ebe19c93d795fbe967846084fbc7943
Patch
https://git.kernel.org/stable/c/cabd1a976375780dabab888784e356f574bbaed8
git.kernel.org
https://git.kernel.org/stable/c/cfa745830e45ecb75c061aa34330ee0cac941cc7
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