{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-74364","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2026-08-15T05:44:03.887Z","datePublished":"2026-08-15T05:58:46.926Z","dateUpdated":"2026-08-17T05:46:23.107Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-08-17T05:46:23.107Z"},"descriptions":[{"lang":"en","value":"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->excl_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->sha[] is validated against\nthe signed hash while another program on a hostile host rewrites the\nfrozen map's contents through the outer map."}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N","baseScore":7.1,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:L - The flaw is reached only through bpf(2) syscalls (BPF_MAP_CREATE, BPF_MAP_UPDATE_ELEM, BPF_PROG_LOAD) and runtime BPF helpers on map-in-map structures, which per kernel guidance is a local attack vector.\nAC:L - Exploitation is a reliable, attacker-controlled sequence (create outer map-of-maps, insert exclusive inner map FD, load program referencing only outer map, lookup/mutate inner map) with no races or layout dependencies.\nPR:L - Triggering the vulnerable map-in-map paths requires local BPF privileges (typically CAP_BPF); per kernel guidance this is Low because CAP_BPF can be obtained by unprivileged users via user namespaces, not only init-namespace root.\nUI:N - No victim interaction is required; a local attacker with BPF access can create the outer map, insert the exclusive inner map, and mutate it through an unrelated loaded program without actions by other users.\nS:U - The impact is bypass of BPF exclusive-map and signed-loader integrity controls within the kernel BPF subsystem, not crossing a VM, container-to-host, or IOMMU security boundary.\nC:H - An unrelated BPF program can bpf_map_lookup_elem() an exclusive inner map via map-in-map indirection and read its full contents, including signed metadata and hashes that must remain confidential to unauthorized programs.\nI:H - The same indirection allows bpf_map_update_elem() on an exclusive map bound to a different program digest, defeating exclusivity and enabling rewrite of signed-loader metadata (map->sha[]) and other protected map state.\nA:N - This is an access-control bypass without memory corruption, use-after-free, or kernel panic; exploitation does not inherently cause crashes, hangs, or denial of kernel availability."}]}],"affected":[{"product":"Linux","vendor":"Linux","defaultStatus":"unaffected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["kernel/bpf/map_in_map.c"],"versions":[{"version":"baefdbdf6812e120c9fba9cfb101d3656f478026","lessThan":"3a0f73d27a8d379a8852a378b3c3208143e3b3b2","status":"affected","versionType":"git"},{"version":"baefdbdf6812e120c9fba9cfb101d3656f478026","lessThan":"7c58ace08f180f8e249e714d1623388362f9d807","status":"affected","versionType":"git"},{"version":"baefdbdf6812e120c9fba9cfb101d3656f478026","lessThan":"9a3c3c49c333760c8944dadacbe114c1884546ef","status":"affected","versionType":"git"}]},{"product":"Linux","vendor":"Linux","defaultStatus":"affected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["kernel/bpf/map_in_map.c"],"versions":[{"version":"6.18","status":"affected"},{"version":"0","lessThan":"6.18","status":"unaffected","versionType":"semver"},{"version":"6.18.40","lessThanOrEqual":"6.18.*","status":"unaffected","versionType":"semver"},{"version":"7.1.5","lessThanOrEqual":"7.1.*","status":"unaffected","versionType":"semver"},{"version":"7.2","lessThanOrEqual":"*","status":"unaffected","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.18","versionEndExcluding":"6.18.40"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.18","versionEndExcluding":"7.1.5"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.18","versionEndExcluding":"7.2"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/3a0f73d27a8d379a8852a378b3c3208143e3b3b2"},{"url":"https://git.kernel.org/stable/c/7c58ace08f180f8e249e714d1623388362f9d807"},{"url":"https://git.kernel.org/stable/c/9a3c3c49c333760c8944dadacbe114c1884546ef"}],"title":"bpf: Reject exclusive maps as inner maps in map-in-map","x_generator":{"engine":"bippy-1.2.0"}}}}