What’s Vulnerable › Vulnerabilities
CVE-2026-23204: net/sched: cls_u32: use skb_header_pointer_careful()
- Severity: high (CVSS 7.1 v3.1)
- Exploited in the wild: not listed in CISA KEV
- EPSS: 0.2% probability of exploitation in the next 30 days
- Public exploit or detection template: none known
- Published: 2026-02-14 · updated 2026-10-19
- Weakness: CWE-125
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
Affected products
- Linux kernel: from 2.6.35.1 before 6.6.124; from 6.7 before 6.12.70; from 6.13 before 6.18.10; 2.6.35, 2.6.35-rc2, 2.6.35-rc3, 2.6.35-rc4, 2.6.35-rc5, 2.6.35-rc6 (+8) — fixed in 6.12.70, 6.18.10, 6.6.124
How to fix
Upgrade to a fixed version: Linux kernel 6.12.70, 6.18.10, 6.6.124. Check the vendor advisory for mitigations.
References
- https://git.kernel.org/stable/c/13336a6239b9d7c6e61483017bb8bdfe3ceb10a5
- https://git.kernel.org/stable/c/29681ed51e737be14d18ecd1c304c57002e4b72c
- https://git.kernel.org/stable/c/66e4b63d61c15de6ca5332d9ca6db59a404d7136
- https://git.kernel.org/stable/c/8a672f177ebe19c93d795fbe967846084fbc7943
- https://git.kernel.org/stable/c/cabd1a976375780dabab888784e356f574bbaed8
- https://git.kernel.org/stable/c/cfa745830e45ecb75c061aa34330ee0cac941cc7
- https://git.kernel.org/stable/c/e41a23e61259f5526af875c3b86b3d42a9bae0e5
- https://cert-portal.siemens.com/productcert/html/ssa-019113.html
- https://cert-portal.siemens.com/productcert/html/ssa-082556.html
- https://cert-portal.siemens.com/productcert/html/ssa-457936.html
- https://cert-portal.siemens.com/productcert/html/ssa-784472.html
Get alerted when CVE-2026-23204 or the next vulnerability affects your stack