{"apiVersion":"1.0","identifier":"CVE-2026-74371","description":"In the Linux kernel, the following vulnerability has been resolved: bpf: fix BPF_PROG_QUERY OOB write and cgroup backward compat BPF_PROG_QUERY writes back the -query.revision- field unconditionally to userspace. If userspace passes a smaller -bpf_attr- structure (e.g. 40 bytes, which was the layout before the addition of -query.revision-), the kernel performs an out-of-bounds write. Fix this by propagating the user-provided attribute size -uattr_size- down to the cgroup query handlers, and conditionally skipping writing the revision field to userspace when the provided buffer size is insufficient. query.revision in bpf_mprog_query is structurally identical to the cgroup case: a late tail field, written unconditionally. But the backward-compat hazard is not the same. The min-historical-size test is per command, and bpf_mprog_query only serves attach types that were born with revision in the struct: - tcx_prog_query -> BPF_TCX_INGRESS/EGRESS - netkit_prog_query -> BPF_NETKIT_PRIMARY/PEER tcx, netkit, the revision field, and bpf_mprog_query itself all landed in the same v6.6 merge window (053c8e1f235d added the mprog query API + revision; tcx in e420bed02507, netkit in 35dfaad7188c). There has never been a tcx/netkit BPF_PROG_QUERY userspace that doesn-t know about revision. So for these commands the minimum legitimate struct already covers offset 56-64 — no old binary can be broken here. Contrast with cgroup: BPF_PROG_QUERY on cgroup attach types shipped in 2017; revision write-back was bolted on years later (120933984460). That path has a real population of pre-revision callers.","publishedAt":"2026-08-15T06:22:38","lastModifiedAt":"2026-08-17T06:19:31","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-74371","cvssScore":7.8,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","epssProbability":0.00127,"riskScore":0.79,"affectedProduct":"Linux kernel","affectedVersions":"unknown","vulnerabilityType":"Kernel","operatingSystems":[],"links":{"self":"https://www.redsauce.net/api/cves/CVE-2026-74371","webPages":{"es":"https://www.redsauce.net/es/cves/CVE-2026-74371","en":"https://www.redsauce.net/en/cves/CVE-2026-74371","fr":"https://www.redsauce.net/fr/cves/CVE-2026-74371","pt":"https://www.redsauce.net/pt/cves/CVE-2026-74371","de":"https://www.redsauce.net/de/cves/CVE-2026-74371","sk":"https://www.redsauce.net/sk/cves/CVE-2026-74371","el":"https://www.redsauce.net/el/cves/CVE-2026-74371"},"source":"https://nvd.nist.gov/vuln/detail/CVE-2026-74371"}}