{"apiVersion":"1.0","identifier":"CVE-2026-72427","description":"In the Linux kernel, the following vulnerability has been resolved: bpf: Fix effective prog array index with BPF_F_PREORDER replace_effective_prog() and purge_effective_progs() located the slot in the effective array by walking the program hlist and counting entries linearly. That count does not match the array layout: compute_effective_ progs() places BPF_F_PREORDER programs at the front (ancestor cgroup first, attach order within a cgroup) and the rest after them (descendant cgroup first). So when a preorder program is present, the linear hlist position no longer equals the program-s index in the effective array. For replace_effective_prog() (bpf_link_update()) this overwrote the wrong slot, corrupting the effective order. For purge_effective_progs(), it could dummy out a slot belonging to a different program and leave the detached program in the array while bpf_prog_put() drops its reference, i.e. a use-after-free. Fix both by replaying compute_effective_progs()-s placement (including the per-cgroup preorder reversal) in a shared effective_prog_pos() helper. Identify the entry by its struct bpf_prog_list pointer rather than by (prog, link) value, so the lookup resolves to exactly the attachment the syscall selected even when the same bpf_prog is attached to several cgroups in the hierarchy.","publishedAt":"2026-08-15T06:22:16","lastModifiedAt":"2026-08-17T06:19:09","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-72427","cvssScore":7.8,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","epssProbability":0.00134,"riskScore":0.79,"affectedProduct":"Linux kernel","affectedVersions":"unknown","vulnerabilityType":"Kernel","operatingSystems":[],"links":{"self":"https://www.redsauce.net/api/cves/CVE-2026-72427","webPages":{"es":"https://www.redsauce.net/es/cves/CVE-2026-72427","en":"https://www.redsauce.net/en/cves/CVE-2026-72427","fr":"https://www.redsauce.net/fr/cves/CVE-2026-72427","pt":"https://www.redsauce.net/pt/cves/CVE-2026-72427","de":"https://www.redsauce.net/de/cves/CVE-2026-72427","sk":"https://www.redsauce.net/sk/cves/CVE-2026-72427","el":"https://www.redsauce.net/el/cves/CVE-2026-72427"},"source":"https://nvd.nist.gov/vuln/detail/CVE-2026-72427"}}