{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-64556", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-07-19T15:36:31.796Z", "datePublished": "2026-07-29T08:01:46.864Z", "dateUpdated": "2026-08-05T12:43:01.776Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T12:43:01.776Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nperf/core: Detach event groups during remove_on_exec\n\nperf_event_remove_on_exec() removes events by calling\nperf_event_exit_event(). For top-level events, this removes the event from\nthe context with DETACH_EXIT only.\n\nThis can leave inconsistent group state when a removed event is a group\nleader and the group contains siblings without remove_on_exec. If the group\nwas active, the surviving siblings can remain active and attached to the\nremoved leader's sibling list, but are no longer represented by a valid\ngroup leader on the PMU context active lists.\n\nA later close of the removed leader uses DETACH_GROUP and can promote the\nstill-active siblings from this stale group state. The next schedule-in can\nthen add an already-linked active_list entry again, corrupting the PMU\ncontext active list.\n\nWith DEBUG_LIST enabled, this is caught as a list_add double-add in\nmerge_sched_in().\n\nFix this by detaching group relationships when remove_on_exec removes an\nevent. This preserves the existing task-exit and revoke behavior, while\nensuring surviving siblings are ungrouped before the removed event leaves\nthe context."}], "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 triggered entirely through local syscalls \u2014 `perf_event_open(2)` to build the event group and `execve(2)`/`close(2)` to trigger the stale-group corruption. No network or physical vector is involved.\nAC:L - The attacker controls the entire deterministic sequence: create a pinned/enabled group with a `remove_on_exec` leader plus non-`remove_on_exec` siblings, exec, then close the leader. No race the attacker cannot influence is required.\nPR:L - An unprivileged user can open perf events on their own task with `exclude_kernel=1` even at the default `perf_event_paranoid=2`, requiring no capability. Basic local user access suffices.\nUI:N - The attacking process performs every step itself (open, exec, close); no action from any other user is needed.\nS:U - The corruption stays within the kernel's own security authority (PMU context list in kernel heap); it does not cross a hypervisor/IOMMU/sandbox boundary.\nC:H - Corrupting the doubly-linked active list of `perf_event` objects yields pointer manipulation over heap-embedded list nodes, which can be leveraged to read adjacent/freed kernel memory for information disclosure.\nI:H - A double `list_add`/subsequent list operations on a corrupted list provide write-what-where-style primitives against attacker-influenceable heap objects, enabling arbitrary modification and control-flow hijack.\nA:H - The list corruption reliably produces a kernel crash/oops (caught as a list_add double-add under DEBUG_LIST, silent corruption and panic otherwise), causing denial of service."}]}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["kernel/events/core.c"], "versions": [{"version": "2e498d0a74e5b88a6689ae1b811f247f91ff188e", "lessThan": "4cdb1b3ab96eb1b7eb70bc5c82fede334bd60df2", "status": "affected", "versionType": "git"}, {"version": "2e498d0a74e5b88a6689ae1b811f247f91ff188e", "lessThan": "39358e856fb89e62e3c8d7389a2dc4ec33dbe90e", "status": "affected", "versionType": "git"}, {"version": "2e498d0a74e5b88a6689ae1b811f247f91ff188e", "lessThan": "a2d5d3ee7b6e3953114726b1521e62123ab5b043", "status": "affected", "versionType": "git"}, {"version": "2e498d0a74e5b88a6689ae1b811f247f91ff188e", "lessThan": "06ccef0434e98058ddae7bcebc901f93d22b7653", "status": "affected", "versionType": "git"}, {"version": "2e498d0a74e5b88a6689ae1b811f247f91ff188e", "lessThan": "037a3c43edfb597665dd34457cd22b14692f2ba3", "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/events/core.c"], "versions": [{"version": "5.13", "status": "affected"}, {"version": "0", "lessThan": "5.13", "status": "unaffected", "versionType": "semver"}, {"version": "6.6.145", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.12.96", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.18.39", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.1.4", "lessThanOrEqual": "7.1.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.2-rc2", "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": "5.13", "versionEndExcluding": "6.6.145"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.13", "versionEndExcluding": "6.12.96"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.13", "versionEndExcluding": "6.18.39"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.13", "versionEndExcluding": "7.1.4"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.13", "versionEndExcluding": "7.2-rc2"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/4cdb1b3ab96eb1b7eb70bc5c82fede334bd60df2"}, {"url": "https://git.kernel.org/stable/c/39358e856fb89e62e3c8d7389a2dc4ec33dbe90e"}, {"url": "https://git.kernel.org/stable/c/a2d5d3ee7b6e3953114726b1521e62123ab5b043"}, {"url": "https://git.kernel.org/stable/c/06ccef0434e98058ddae7bcebc901f93d22b7653"}, {"url": "https://git.kernel.org/stable/c/037a3c43edfb597665dd34457cd22b14692f2ba3"}], "title": "perf/core: Detach event groups during remove_on_exec", "x_generator": {"engine": "bippy-1.2.0"}}}}

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{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "Linux", "programFiles": ["kernel/events/core.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"lessThan": "4cdb1b3ab96eb1b7eb70bc5c82fede334bd60df2", "status": "affected", "version": "2e498d0a74e5b88a6689ae1b811f247f91ff188e", "versionType": "git"}, {"lessThan": "39358e856fb89e62e3c8d7389a2dc4ec33dbe90e", "status": "affected", "version": "2e498d0a74e5b88a6689ae1b811f247f91ff188e", "versionType": "git"}, {"lessThan": "a2d5d3ee7b6e3953114726b1521e62123ab5b043", "status": "affected", "version": "2e498d0a74e5b88a6689ae1b811f247f91ff188e", "versionType": "git"}, {"lessThan": "06ccef0434e98058ddae7bcebc901f93d22b7653", "status": "affected", "version": "2e498d0a74e5b88a6689ae1b811f247f91ff188e", "versionType": "git"}, {"lessThan": "037a3c43edfb597665dd34457cd22b14692f2ba3", "status": "affected", "version": "2e498d0a74e5b88a6689ae1b811f247f91ff188e", "versionType": "git"}]}, {"defaultStatus": "affected", "product": "Linux", "programFiles": ["kernel/events/core.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"status": "affected", "version": "5.13"}, {"lessThan": "5.13", "status": "unaffected", "version": "0", "versionType": "semver"}, {"lessThanOrEqual": "6.6.*", "status": "unaffected", "version": "6.6.145", "versionType": "semver"}, {"lessThanOrEqual": "6.12.*", "status": "unaffected", "version": "6.12.96", "versionType": "semver"}, {"lessThanOrEqual": "6.18.*", "status": "unaffected", "version": "6.18.39", "versionType": "semver"}, {"lessThanOrEqual": "7.1.*", "status": "unaffected", "version": "7.1.4", "versionType": "semver"}, {"lessThanOrEqual": "*", "status": "unaffected", "version": "7.2-rc2", "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\nperf/core: Detach event groups during remove_on_exec\n\nperf_event_remove_on_exec() removes events by calling\nperf_event_exit_event(). For top-level events, this removes the event from\nthe context with DETACH_EXIT only.\n\nThis can leave inconsistent group state when a removed event is a group\nleader and the group contains siblings without remove_on_exec. If the group\nwas active, the surviving siblings can remain active and attached to the\nremoved leader's sibling list, but are no longer represented by a valid\ngroup leader on the PMU context active lists.\n\nA later close of the removed leader uses DETACH_GROUP and can promote the\nstill-active siblings from this stale group state. The next schedule-in can\nthen add an already-linked active_list entry again, corrupting the PMU\ncontext active list.\n\nWith DEBUG_LIST enabled, this is caught as a list_add double-add in\nmerge_sched_in().\n\nFix this by detaching group relationships when remove_on_exec removes an\nevent. This preserves the existing task-exit and revoke behavior, while\nensuring surviving siblings are ungrouped before the removed event leaves\nthe context."}], "id": "CVE-2026-64556", "lastModified": "2026-07-30T06:25:59.350", "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": "2026-07-29T09:16:30.153", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/037a3c43edfb597665dd34457cd22b14692f2ba3"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/06ccef0434e98058ddae7bcebc901f93d22b7653"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/39358e856fb89e62e3c8d7389a2dc4ec33dbe90e"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/4cdb1b3ab96eb1b7eb70bc5c82fede334bd60df2"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/a2d5d3ee7b6e3953114726b1521e62123ab5b043"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Received"}

{"bugzilla": {"description": "kernel: perf/core: Detach event groups during remove_on_exec", "id": "2508319", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2508319"}, "csaw": false, "cvss3": {"cvss3_base_score": "7.0", "cvss3_scoring_vector": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H", "status": "draft"}, "cwe": "CWE-663", "details": ["A flaw was found in the Linux kernel's performance monitoring unit (PMU) subsystem. This vulnerability occurs when a performance event group leader is removed during process execution, but its associated events (siblings) remain active and linked to a stale list. This inconsistent state can lead to a corruption of the PMU context active list, potentially causing system instability or a denial of service. A local attacker could potentially exploit this to disrupt system operations."], "name": "CVE-2026-64556", "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": "Under investigation", "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": "Affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/a:redhat:hummingbird:1", "fix_state": "Fix deferred", "impact": "moderate", "package_name": "erlang27", "product_name": "Red Hat Hardened Images"}], "public_date": "2026-07-29T00:00:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-64556\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-64556\nhttps://lore.kernel.org/linux-cve-announce/2026072939-CVE-2026-64556-0f2c@gregkh/T"], "threat_severity": "Important"}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[2e498d0a74e5b88a6689ae1b811f247f91ff188e,4cdb1b3ab96eb1b7eb70bc5c82fede334bd60df2)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[2e498d0a74e5b88a6689ae1b811f247f91ff188e,39358e856fb89e62e3c8d7389a2dc4ec33dbe90e)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[2e498d0a74e5b88a6689ae1b811f247f91ff188e,a2d5d3ee7b6e3953114726b1521e62123ab5b043)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[2e498d0a74e5b88a6689ae1b811f247f91ff188e,06ccef0434e98058ddae7bcebc901f93d22b7653)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[2e498d0a74e5b88a6689ae1b811f247f91ff188e,037a3c43edfb597665dd34457cd22b14692f2ba3)"}}], "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": "5.13"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[0,5.13)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.6.145,6.7.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.12.96,6.13.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.18.39,6.19.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[7.1.4,7.2.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[7.2-rc2,*]"}}], "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": "2026-07-29T09:30:17.880059+00:00", "updated": "2026-08-02T08:15:17.654145+00:00", "vendors": ["linux", "linux$PRODUCT$linux_kernel"]}