CVE-2026-45951

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-45951", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-05-13T15:03:33.088Z", "datePublished": "2026-05-27T12:18:07.255Z", "dateUpdated": "2026-08-05T12:28:53.157Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T12:28:53.157Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Fix a potential use-after-free of BTF object\n\nRefcounting in the check_pseudo_btf_id() function is incorrect:\nthe __check_pseudo_btf_id() function might get called with a zero\nrefcounted btf. Fix this, and patch related code accordingly.\n\nv3: rephrase a comment (AI)\nv2: fix a refcount leak introduced in v1 (AI)"}], "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 vulnerability is reached only through the local bpf() syscall (BPF_PROG_LOAD verifying a BPF_PSEUDO_BTF_ID ldimm64 instruction); there is no network, adjacent, or physical input path.\nAC:L - Triggering the UAF requires racing a concurrent close of the BTF fd against the verifier, but the attacker controls both sides (loading thread and closing thread) and can retry/heap-spray indefinitely, so per kernel guidance an attacker-created race is Low.\nPR:L - Obtaining a BTF fd (BPF_BTF_LOAD) and loading the program both require CAP_BPF, which can be delegated to a non-init user namespace via BPF token/bpffs in reasonable container deployments, making this reachable to a non-host-root local user.\nUI:N - The attacker performs the entire attack themselves by issuing bpf() syscalls and closing the fd; no victim action is required.\nS:U - The use-after-free and its consequences are confined to the kernel's own memory and security authority; no boundary such as VM or IOMMU is crossed.\nC:H - The freed BTF object is dereferenced (type/name/kallsyms lookups) and can be reallocated with attacker-controlled data, giving a kernel-memory read primitive characteristic of a use-after-free.\nI:H - The UAF causes a refcount increment on freed memory and stores a dangling btf pointer into env->used_btfs[] that is used later, enabling heap grooming and type confusion that can be leveraged into a write/control-flow primitive.\nA:H - Dereferencing the freed BTF object reliably crashes the kernel (oops/panic), so availability impact is High."}]}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["kernel/bpf/verifier.c"], "versions": [{"version": "76145f7255326761dafb76721a785799d8a00d5f", "lessThan": "eac65c272f3b49021a843cba5107d63627395e0e", "status": "affected", "versionType": "git"}, {"version": "76145f7255326761dafb76721a785799d8a00d5f", "lessThan": "9ff46ffeecdb1802d6e26183177935b948a12e7f", "status": "affected", "versionType": "git"}, {"version": "76145f7255326761dafb76721a785799d8a00d5f", "lessThan": "ccd2d799ed4467c07f5ee18c2f5c59bcc990822c", "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/verifier.c"], "versions": [{"version": "6.14", "status": "affected"}, {"version": "0", "lessThan": "6.14", "status": "unaffected", "versionType": "semver"}, {"version": "6.18.14", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.19.4", "lessThanOrEqual": "6.19.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.0", "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": "6.14", "versionEndExcluding": "6.18.14"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.14", "versionEndExcluding": "6.19.4"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.14", "versionEndExcluding": "7.0"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/eac65c272f3b49021a843cba5107d63627395e0e"}, {"url": "https://git.kernel.org/stable/c/9ff46ffeecdb1802d6e26183177935b948a12e7f"}, {"url": "https://git.kernel.org/stable/c/ccd2d799ed4467c07f5ee18c2f5c59bcc990822c"}], "title": "bpf: Fix a potential use-after-free of BTF object", "x_generator": {"engine": "bippy-1.2.0"}}}}

{}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "Linux", "programFiles": ["kernel/bpf/verifier.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"lessThan": "eac65c272f3b49021a843cba5107d63627395e0e", "status": "affected", "version": "76145f7255326761dafb76721a785799d8a00d5f", "versionType": "git"}, {"lessThan": "9ff46ffeecdb1802d6e26183177935b948a12e7f", "status": "affected", "version": "76145f7255326761dafb76721a785799d8a00d5f", "versionType": "git"}, {"lessThan": "ccd2d799ed4467c07f5ee18c2f5c59bcc990822c", "status": "affected", "version": "76145f7255326761dafb76721a785799d8a00d5f", "versionType": "git"}]}, {"defaultStatus": "affected", "product": "Linux", "programFiles": ["kernel/bpf/verifier.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"status": "affected", "version": "6.14"}, {"lessThan": "6.14", "status": "unaffected", "version": "0", "versionType": "semver"}, {"lessThanOrEqual": "6.18.*", "status": "unaffected", "version": "6.18.14", "versionType": "semver"}, {"lessThanOrEqual": "6.19.*", "status": "unaffected", "version": "6.19.4", "versionType": "semver"}, {"lessThanOrEqual": "*", "status": "unaffected", "version": "7.0", "versionType": "original_commit_for_fix"}]}], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "configurations": [{"nodes": [{"cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "matchCriteriaId": "C969BF0A-760D-435A-9705-6ED20216C1BB", "versionEndExcluding": "6.18.14", "versionStartIncluding": "6.14", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "matchCriteriaId": "672A3E79-EC03-479D-8503-361DFBDC8092", "versionEndExcluding": "6.19.4", "versionStartIncluding": "6.19", "vulnerable": true}], "negate": false, "operator": "OR"}]}], "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Fix a potential use-after-free of BTF object\n\nRefcounting in the check_pseudo_btf_id() function is incorrect:\nthe __check_pseudo_btf_id() function might get called with a zero\nrefcounted btf. Fix this, and patch related code accordingly.\n\nv3: rephrase a comment (AI)\nv2: fix a refcount leak introduced in v1 (AI)"}], "id": "CVE-2026-45951", "lastModified": "2026-06-17T10:52:47.033", "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": "2026-05-27T14:17:11.613", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/9ff46ffeecdb1802d6e26183177935b948a12e7f"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/ccd2d799ed4467c07f5ee18c2f5c59bcc990822c"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/eac65c272f3b49021a843cba5107d63627395e0e"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Analyzed", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-416"}], "source": "nvd@nist.gov", "type": "Primary"}]}

{"bugzilla": {"description": "kernel: bpf: Fix a potential use-after-free of BTF object", "id": "2482134", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2482134"}, "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-911", "details": ["A flaw was found in the Linux kernel, specifically within its BPF (Berkeley Packet Filter) subsystem. This vulnerability, a use-after-free, arises from incorrect reference counting in the `check_pseudo_btf_id()` function. It allows a local attacker to potentially corrupt memory, which could lead to privilege escalation or a system crash (denial of service)."], "name": "CVE-2026-45951", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:6", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 6"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 9"}], "public_date": "2026-05-27T00:00:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-45951\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-45951\nhttps://lore.kernel.org/linux-cve-announce/2026052731-CVE-2026-45951-dc78@gregkh/T"], "statement": "The default Red Hat Enterprise Linux kernel prevents unprivileged users from being able to use eBPF by the kernel.unprivileged_bpf_disabled sysctl. This would require a privileged user with CAP_SYS_ADMIN or root to be able to abuse this flaw reducing its attack space.\nFor the Red Hat Enterprise Linux 9 to confirm the current state, inspect the sysctl with the command:\ncat /proc/sys/kernel/unprivileged_bpf_disabled\nThe setting of 1 would mean that unprivileged users can not use eBPF, mitigating the flaw.", "threat_severity": "Moderate"}

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