{ "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" } } } }