{"id":"CVE-2026-74364","summary":"bpf: Reject exclusive maps as inner maps in map-in-map","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Reject exclusive maps as inner maps in map-in-map\n\nAn exclusive map (created with excl_prog_hash) is bound to a single\nprogram by hash: check_map_prog_compatibility() refuses to load any\nprogram whose digest does not match map-\u003eexcl_prog_sha. That check\nonly runs for maps a program references directly, i.e. its used_maps.\nA map reached at runtime through a map-of-maps is never in used_maps,\nand bpf_map_meta_equal() does not consider excl_prog_sha, so an\nexclusive map can be inserted into a non-exclusive outer map and\nthen looked up and mutated by an unrelated program, bypassing the\nexclusivity guarantee.\n\nFor the signed loader this defeats the metadata map exclusivity check\nadded in the signed loader: the cached map-\u003esha[] is validated against\nthe signed hash while another program on a hostile host rewrites the\nfrozen map's contents through the outer map.","modified":"2026-08-18T03:56:57.230061496Z","published":"2026-08-15T05:58:46.926Z","database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/74xxx/CVE-2026-74364.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/3a0f73d27a8d379a8852a378b3c3208143e3b3b2"},{"type":"WEB","url":"https://git.kernel.org/stable/c/7c58ace08f180f8e249e714d1623388362f9d807"},{"type":"WEB","url":"https://git.kernel.org/stable/c/9a3c3c49c333760c8944dadacbe114c1884546ef"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/74xxx/CVE-2026-74364.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-74364"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"baefdbdf6812e120c9fba9cfb101d3656f478026"},{"fixed":"3a0f73d27a8d379a8852a378b3c3208143e3b3b2"},{"fixed":"7c58ace08f180f8e249e714d1623388362f9d807"},{"fixed":"9a3c3c49c333760c8944dadacbe114c1884546ef"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-74364.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"6.18.0"},{"fixed":"6.18.40"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"7.1.5"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-74364.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N"}]}