CVE-2026-89579

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-89579", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-11T19:38:34.728Z", "datePublished": "2026-09-11T19:44:46.110Z", "dateUpdated": "2026-10-19T08:49:12.203Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-19T08:49:12.203Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Harden bloom filter sizing and indexing on 32-bit kernels\n\nbloom_map_alloc() has two 32-bit-specific problems when the computed\nbitmap reaches the U32_MAX fallback case.\n\nFirst, BITS_TO_BYTES(U32_MAX) is evaluated with 32-bit arithmetic. The\naddition performed by DIV_ROUND_UP wraps, so the map allocates only the\nfixed-size bloom filter object while keeping bitset_mask == U32_MAX.\nSubsequent updates can then write past the allocated object.\n\nSecond, fixing only the allocation size is not sufficient. The bloom hash\nis a u32, but set_bit() takes a signed long bit number and x86 test_bit()\neventually feeds the index to variable_test_bit(long, ...). On 32-bit\nkernels, hashes in [0x80000000, U32_MAX] therefore become negative bit\noffsets. x86 bt/bts with a memory operand interpret those offsets relative\nto the supplied base, so a map with bitset_mask == U32_MAX can read or\nwrite before bloom->bitset even after allocating the full 512 MiB bitmap.\n\nKeep the U32_MAX fallback, but split each hash into a word pointer and an\nin-word bit number before calling test_bit() or set_bit(). The bitops\nargument is then always in [0, BITS_PER_LONG - 1], while BIT_WORD(h) still\nselects the intended word in the full bitmap.\n\nCompute the bitset size from (u64)bitset_mask + 1 before passing the final\nsize to bpf_map_area_alloc(). This fixes the original under-allocation and\nkeeps the allocated storage consistent with the addressable bitset.\n\nExploitation note: local privilege escalation is possible on a 32-bit x86\nkernel using the under-allocation bug from a binary with CAP_BPF."}], "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:H", "baseScore": 7.8, "baseSeverity": "HIGH"}, "scenarios": [{"lang": "en", "value": "AV:L - The bug is reached only via local bpf(2) syscalls: BPF_MAP_CREATE of BPF_MAP_TYPE_BLOOM_FILTER, then BPF_MAP_UPDATE_ELEM/LOOKUP_ELEM which call bloom_map_push_elem/peek_elem. Per kernel CNA guidance BPF is Local, not network-reachable.\nAC:L - On a 32-bit kernel the attacker deterministically forces the U32_MAX bitmap fallback with a large max_entries so BITS_TO_BYTES wraps and under-allocates; BPF_F_ZERO_SEED and chosen values then drive set_bit/test_bit to selected out-of-bounds indexes with no race or uncontrolled layout.\nPR:L - Creating a bloom-filter map requires CAP_BPF in map_create_alloc (bpf_token_capable). Per kernel guidance this is Low because CAP_BPF is obtainable via user namespaces and BPF token delegation, not only init-namespace root.\nUI:N - The attacker creates the undersized bloom map and issues lookup/update syscalls from their own process; no victim action such as mounting a filesystem or opening a file is required.\nS:U - The out-of-bounds bit set/test corrupts kernel heap around the undersized bloom object on the same host. This is standard kernel memory corruption and privilege escalation, not a VM escape or IOMMU boundary bypass.\nC:H - With bitset_mask==U32_MAX and a near-empty allocation, bloom_map_peek_elem's test_bit is an out-of-bounds kernel bit-read oracle, and the matching OOB writes enable heap disclosure; kernel guidance rates such memory corruption as High confidentiality impact.\nI:H - bloom_map_push_elem's set_bit writes past (and on 32-bit x86, before) the allocated object across a huge range, a controllable OOB write. The fix commit documents local privilege escalation from CAP_BPF on 32-bit x86.\nA:H - The same unbounded set_bit/test_bit indexes unmapped pages around the undersized kmalloc object and reliably produces a kernel oops or panic, which is High availability impact per kernel guidance."}]}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["kernel/bpf/bloom_filter.c"], "versions": [{"version": "9330986c03006ab1d33d243b7cfe598a7a3c1baa", "lessThan": "a6183bc683f97f4317f7e84939ca7fff37c5688b", "status": "affected", "versionType": "git"}, {"version": "9330986c03006ab1d33d243b7cfe598a7a3c1baa", "lessThan": "80551bf8912c42d1e3d55eec6fa3c40f306c3de8", "status": "affected", "versionType": "git"}, {"version": "9330986c03006ab1d33d243b7cfe598a7a3c1baa", "lessThan": "3b7a13eccfcf97714ffc1ca6aa663d66d4a30e29", "status": "affected", "versionType": "git"}, {"version": "9330986c03006ab1d33d243b7cfe598a7a3c1baa", "lessThan": "272fcb4ba6fab678db0eb966dc81c4c804bef64a", "status": "affected", "versionType": "git"}, {"version": "9330986c03006ab1d33d243b7cfe598a7a3c1baa", "lessThan": "dff481e12b3f127739f6a4ea7cef2c25dc12e056", "status": "affected", "versionType": "git"}, {"version": "9330986c03006ab1d33d243b7cfe598a7a3c1baa", "lessThan": "11c1e836710dcba03e50454a4eedfdbaf8d3050e", "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/bloom_filter.c"], "versions": [{"version": "5.16", "status": "affected"}, {"version": "0", "lessThan": "5.16", "status": "unaffected", "versionType": "semver"}, {"version": "6.1.188", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.6.157", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.12.109", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.18.50", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.2.4", "lessThanOrEqual": "7.2.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.3", "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": "5.16", "versionEndExcluding": "6.1.188"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.16", "versionEndExcluding": "6.6.157"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.16", "versionEndExcluding": "6.12.109"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.16", "versionEndExcluding": "6.18.50"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.16", "versionEndExcluding": "7.2.4"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.16", "versionEndExcluding": "7.3"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/a6183bc683f97f4317f7e84939ca7fff37c5688b"}, {"url": "https://git.kernel.org/stable/c/80551bf8912c42d1e3d55eec6fa3c40f306c3de8"}, {"url": "https://git.kernel.org/stable/c/3b7a13eccfcf97714ffc1ca6aa663d66d4a30e29"}, {"url": "https://git.kernel.org/stable/c/272fcb4ba6fab678db0eb966dc81c4c804bef64a"}, {"url": "https://git.kernel.org/stable/c/dff481e12b3f127739f6a4ea7cef2c25dc12e056"}, {"url": "https://git.kernel.org/stable/c/11c1e836710dcba03e50454a4eedfdbaf8d3050e"}], "title": "bpf: Harden bloom filter sizing and indexing on 32-bit kernels", "x_generator": {"engine": "bippy-1.2.0"}}}}

{}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "Linux", "programFiles": ["kernel/bpf/bloom_filter.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"lessThan": "a6183bc683f97f4317f7e84939ca7fff37c5688b", "status": "affected", "version": "9330986c03006ab1d33d243b7cfe598a7a3c1baa", "versionType": "git"}, {"lessThan": "80551bf8912c42d1e3d55eec6fa3c40f306c3de8", "status": "affected", "version": "9330986c03006ab1d33d243b7cfe598a7a3c1baa", "versionType": "git"}, {"lessThan": "3b7a13eccfcf97714ffc1ca6aa663d66d4a30e29", "status": "affected", "version": "9330986c03006ab1d33d243b7cfe598a7a3c1baa", "versionType": "git"}, {"lessThan": "272fcb4ba6fab678db0eb966dc81c4c804bef64a", "status": "affected", "version": "9330986c03006ab1d33d243b7cfe598a7a3c1baa", "versionType": "git"}, {"lessThan": "dff481e12b3f127739f6a4ea7cef2c25dc12e056", "status": "affected", "version": "9330986c03006ab1d33d243b7cfe598a7a3c1baa", "versionType": "git"}, {"lessThan": "11c1e836710dcba03e50454a4eedfdbaf8d3050e", "status": "affected", "version": "9330986c03006ab1d33d243b7cfe598a7a3c1baa", "versionType": "git"}]}, {"defaultStatus": "affected", "product": "Linux", "programFiles": ["kernel/bpf/bloom_filter.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"status": "affected", "version": "5.16"}, {"lessThan": "5.16", "status": "unaffected", "version": "0", "versionType": "semver"}, {"lessThanOrEqual": "6.1.*", "status": "unaffected", "version": "6.1.188", "versionType": "semver"}, {"lessThanOrEqual": "6.6.*", "status": "unaffected", "version": "6.6.157", "versionType": "semver"}, {"lessThanOrEqual": "6.12.*", "status": "unaffected", "version": "6.12.109", "versionType": "semver"}, {"lessThanOrEqual": "6.18.*", "status": "unaffected", "version": "6.18.50", "versionType": "semver"}, {"lessThanOrEqual": "7.2.*", "status": "unaffected", "version": "7.2.4", "versionType": "semver"}, {"lessThanOrEqual": "*", "status": "unaffected", "version": "7.3", "versionType": "original_commit_for_fix"}]}], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Harden bloom filter sizing and indexing on 32-bit kernels\n\nbloom_map_alloc() has two 32-bit-specific problems when the computed\nbitmap reaches the U32_MAX fallback case.\n\nFirst, BITS_TO_BYTES(U32_MAX) is evaluated with 32-bit arithmetic. The\naddition performed by DIV_ROUND_UP wraps, so the map allocates only the\nfixed-size bloom filter object while keeping bitset_mask == U32_MAX.\nSubsequent updates can then write past the allocated object.\n\nSecond, fixing only the allocation size is not sufficient. The bloom hash\nis a u32, but set_bit() takes a signed long bit number and x86 test_bit()\neventually feeds the index to variable_test_bit(long, ...). On 32-bit\nkernels, hashes in [0x80000000, U32_MAX] therefore become negative bit\noffsets. x86 bt/bts with a memory operand interpret those offsets relative\nto the supplied base, so a map with bitset_mask == U32_MAX can read or\nwrite before bloom->bitset even after allocating the full 512 MiB bitmap.\n\nKeep the U32_MAX fallback, but split each hash into a word pointer and an\nin-word bit number before calling test_bit() or set_bit(). The bitops\nargument is then always in [0, BITS_PER_LONG - 1], while BIT_WORD(h) still\nselects the intended word in the full bitmap.\n\nCompute the bitset size from (u64)bitset_mask + 1 before passing the final\nsize to bpf_map_area_alloc(). This fixes the original under-allocation and\nkeeps the allocated storage consistent with the addressable bitset.\n\nExploitation note: local privilege escalation is possible on a 32-bit x86\nkernel using the under-allocation bug from a binary with CAP_BPF."}], "id": "CVE-2026-89579", "lastModified": "2026-10-19T09:17:53.917", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "LOCAL", "availabilityImpact": "HIGH", "baseScore": 7.8, "baseSeverity": "HIGH", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "LOW", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "version": "3.1"}, "exploitabilityScore": 1.8, "impactScore": 5.9, "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "type": "Secondary"}]}, "published": "2026-09-11T20:19:42.127", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/11c1e836710dcba03e50454a4eedfdbaf8d3050e"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/272fcb4ba6fab678db0eb966dc81c4c804bef64a"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/3b7a13eccfcf97714ffc1ca6aa663d66d4a30e29"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/80551bf8912c42d1e3d55eec6fa3c40f306c3de8"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/a6183bc683f97f4317f7e84939ca7fff37c5688b"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/dff481e12b3f127739f6a4ea7cef2c25dc12e056"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Received"}

{"bugzilla": {"description": "kernel: Linux kernel: Local privilege escalation in BPF due to memory corruption", "id": "2532482", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2532482"}, "csaw": false, "cvss3": {"cvss3_base_score": "6.7", "cvss3_scoring_vector": "CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H", "status": "draft"}, "cwe": "CWE-787", "details": ["A flaw was found in the Linux kernel's Berkeley Packet Filter (BPF) component, specifically impacting 32-bit systems. This vulnerability stems from incorrect sizing and indexing of bloom filters, which can lead to out-of-bounds memory access. A local attacker with CAP_BPF capabilities could exploit this to escalate their privileges on the system."], "name": "CVE-2026-89579", "public_date": "2026-09-11T19:44:46Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-89579\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-89579\nhttps://git.kernel.org/stable/c/11c1e836710dcba03e50454a4eedfdbaf8d3050e\nhttps://git.kernel.org/stable/c/272fcb4ba6fab678db0eb966dc81c4c804bef64a\nhttps://git.kernel.org/stable/c/3b7a13eccfcf97714ffc1ca6aa663d66d4a30e29\nhttps://git.kernel.org/stable/c/dff481e12b3f127739f6a4ea7cef2c25dc12e056"], "threat_severity": "Moderate"}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[9330986c03006ab1d33d243b7cfe598a7a3c1baa,3b7a13eccfcf97714ffc1ca6aa663d66d4a30e29)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[9330986c03006ab1d33d243b7cfe598a7a3c1baa,272fcb4ba6fab678db0eb966dc81c4c804bef64a)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[9330986c03006ab1d33d243b7cfe598a7a3c1baa,dff481e12b3f127739f6a4ea7cef2c25dc12e056)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[9330986c03006ab1d33d243b7cfe598a7a3c1baa,11c1e836710dcba03e50454a4eedfdbaf8d3050e)"}}], "enrichment": {"confidence": 99.0, "confidence_source": "inferred", "scores": [{"score": 99.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux_kernel", "vendor": "linux"}, {"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "generic", "value": "5.16"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[0,5.16)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.12.109,6.13.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.18.50,6.19.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[7.2.4,7.3.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[7.3-rc1,*]"}}], "enrichment": {"confidence": 99.0, "confidence_source": "inferred", "scores": [{"score": 99.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux_kernel", "vendor": "linux"}], "created": "2026-09-12T09:30:13.018080+00:00", "updated": "2026-09-15T21:45:17.662696+00:00", "vendors": ["linux", "linux$PRODUCT$linux_kernel"]}