{"apiVersion":"1.0","identifier":"CVE-2026-74544","description":"In the Linux kernel, the following vulnerability has been resolved: net/sched: cls_u32: validate offshift to prevent shift-out-of-bounds u32_change() copies the user-provided tc_u32_sel.offshift (unsigned char, 0-255) into the kernel knode object without bounds validation. When a packet later hits u32_classify() with TC_U32_VAROFFSET set, it evaluates `ntohs(offmask & *data) >> offshift` where the left operand is a 16-bit value promoted to a 32-bit int. Any offshift >= 32 is undefined behavior per C11 6.5.7p3, triggerable by an unprivileged user via user/network namespaces. UBSAN: shift-out-of-bounds in net/sched/cls_u32.c:236:43 shift exponent 32 is too large for 32-bit type int Fix this by rejecting offshift >= 16 during filter creation in u32_change().","publishedAt":"2026-08-15T13:17:59","lastModifiedAt":"2026-08-17T06:19:51","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-74544","cvssScore":7.8,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","epssProbability":0.00121,"riskScore":0.79,"affectedProduct":"Linux kernel","affectedVersions":"unknown","vulnerabilityType":"Kernel","operatingSystems":[],"links":{"self":"https://www.redsauce.net/api/cves/CVE-2026-74544","webPages":{"es":"https://www.redsauce.net/es/cves/CVE-2026-74544","en":"https://www.redsauce.net/en/cves/CVE-2026-74544","fr":"https://www.redsauce.net/fr/cves/CVE-2026-74544","pt":"https://www.redsauce.net/pt/cves/CVE-2026-74544","de":"https://www.redsauce.net/de/cves/CVE-2026-74544","sk":"https://www.redsauce.net/sk/cves/CVE-2026-74544","el":"https://www.redsauce.net/el/cves/CVE-2026-74544"},"source":"https://nvd.nist.gov/vuln/detail/CVE-2026-74544"}}