{"apiVersion":"1.0","identifier":"CVE-2026-74739","description":"In the Linux kernel, the following vulnerability has been resolved: net/sched: cls_u32: skip hash tables in u32_bind_class() u32_walk() enumerates both struct tc_u_hnode and struct tc_u_knode through the walker callback. u32_bind_class() unconditionally casts the passed fh to tc_u_knode and accesses &n->res, so when fh is actually a tc_u_hnode, which has no tcf_result member, this results in a slab-out-of-bounds read of res->classid in tc_cls_bind_class(). The issue can be reproduced with the following commands: tc qdisc add dev lo root handle 1: hfsc tc class add dev lo parent 1: classid 1:1 hfsc sc rate 1000kbit tc filter add dev lo parent 1:1 protocol ip prio 1 u32 match u32 0 0 flowid 1:1 tc class add dev lo parent 1: classid 1:2 hfsc sc rate 2000kbit Fix this by skipping hash tables via the TC_U32_KEY(handle) check.","publishedAt":"2026-08-26T15:16:52","lastModifiedAt":"2026-08-27T06:17:23","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-74739","cvssScore":7.8,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","epssProbability":0.00138,"riskScore":0.79,"affectedProduct":"Linux kernel","affectedVersions":"unknown","vulnerabilityType":"Kernel","operatingSystems":[],"links":{"self":"https://www.redsauce.net/api/cves/CVE-2026-74739","webPages":{"es":"https://www.redsauce.net/es/cves/CVE-2026-74739","en":"https://www.redsauce.net/en/cves/CVE-2026-74739","fr":"https://www.redsauce.net/fr/cves/CVE-2026-74739","pt":"https://www.redsauce.net/pt/cves/CVE-2026-74739","de":"https://www.redsauce.net/de/cves/CVE-2026-74739","sk":"https://www.redsauce.net/sk/cves/CVE-2026-74739","el":"https://www.redsauce.net/el/cves/CVE-2026-74739"},"source":"https://nvd.nist.gov/vuln/detail/CVE-2026-74739"}}