CVE-2026-99238

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-99238", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-25T10:25:14.403Z", "datePublished": "2026-11-02T16:06:42.810Z", "dateUpdated": "2026-11-03T19:13:05.949Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-11-03T19:13:05.949Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ntracing: Hold trace_types_lock when updating modules in persistent instances\n\ntrace_module_record() walks ftrace_trace_arrays from the module notifier\nwithout trace_types_lock. A concurrent rmdir of an instance removes it\nfrom the list and frees it under that lock, so a module load or unload\ncan walk into a freed trace_array."}], "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 - trace_module_record() is reached only from trace_module_notify() on MODULE_STATE_COMING/GOING via load_module()->prepare_coming_module() or delete_module(), i.e. local finit_module/init_module/delete_module or __sock_create()'s request_module(\"net-pf-%d\"). The concurrent free is rmdir(2) on tracefs instances (tracefs_syscall_rmdir()->instance_rmdir()). No protocol message carries the list pointer.\nAC:L - The attacker mkdir()s an instance, then concurrently rmdir()s it so __remove_instance() list_del()+kfree()s the trace_array while another thread loads or unloads a module and trace_module_record() walks ftrace_trace_arrays unlocked. They drive both sides and can retry; a boot/persistent instance is unnecessary because the walk visits every trace_array before checking TRACE_ARRAY_FL_BOOT.\nPR:L - instance_mkdir()/instance_rmdir() (via tracefs_syscall_rmdir) check only VFS DAC on the 0750 instances directory and LOCKDOWN_TRACEFS, not capable(). tracefs_parse_param() uid=/gid= makes a non-root owner of that directory. The COMING notifier also runs after __sock_create()'s request_module(\"net-pf-%d\"), which is not gated by CAP_SYS_MODULE.\nUI:N - The attacker mkdir/rmdir their own /sys/kernel/tracing/instances/<name> and starts the module load or unload (socket() autoload, finit_module, or delete_module) on their own threads. No other user must mount media, open a file, or confirm the action.\nS:U - __remove_instance() kfree()s a host-kernel struct trace_array that trace_module_record() still walks on ftrace_trace_arrays. The resulting heap corruption stays in the tracing subsystem on that host and does not cross a VM, IOMMU, or guest/host boundary.\nC:H - After __remove_instance() kfree()s the kzalloc'd trace_array, trace_module_record() still reads tr->flags and list_for_each_entry follows tr->list.next. Reclaiming that object lets the attacker control those fields and the later tr->scratch/tr->module_delta pointers, which is a use-after-free kernel read.\nI:H - If the reclaimed object's flags include TRACE_ARRAY_FL_BOOT, save_mod() writes mod->name and mod_addr through attacker-controlled tr->scratch; if TRACE_ARRAY_FL_LAST_BOOT is set, make_mod_delta() writes tr->module_delta->delta[]. That use-after-free write is a kernel heap and control-flow primitive.\nA:H - list_for_each_entry on the kfree'd trace_array in trace_module_record(), or save_mod()/make_mod_delta() dereferencing stale tr->scratch, oopses or panics the kernel. The attacker can repeat the rmdir-versus-module-notifier race until that crash hits."}]}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["kernel/trace/trace.c"], "versions": [{"version": "5f3719f697c3fdfae5cd6805f10ac7a04b0f4e43", "lessThan": "57408eac99b0d8a005796346d317d31f0ca4e07a", "status": "affected", "versionType": "git"}, {"version": "5f3719f697c3fdfae5cd6805f10ac7a04b0f4e43", "lessThan": "dab2bd4d67ad5eaa95019a9511f8d379401b5021", "status": "affected", "versionType": "git"}, {"version": "5f3719f697c3fdfae5cd6805f10ac7a04b0f4e43", "lessThan": "244c442f54601a24c86ad90572bf36fc3df41c5e", "status": "affected", "versionType": "git"}, {"version": "5f3719f697c3fdfae5cd6805f10ac7a04b0f4e43", "lessThan": "66877a312ae3c2c3d849e82e882f642ffd4ec3e2", "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/trace/trace.c"], "versions": [{"version": "6.15", "status": "affected"}, {"version": "0", "lessThan": "6.15", "status": "unaffected", "versionType": "semver"}, {"version": "6.18.60", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.2.14", "lessThanOrEqual": "7.2.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.3.1", "lessThanOrEqual": "7.3.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.4-rc1", "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": "6.15", "versionEndExcluding": "6.18.60"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.15", "versionEndExcluding": "7.2.14"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.15", "versionEndExcluding": "7.3.1"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.15", "versionEndExcluding": "7.4-rc1"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/57408eac99b0d8a005796346d317d31f0ca4e07a"}, {"url": "https://git.kernel.org/stable/c/dab2bd4d67ad5eaa95019a9511f8d379401b5021"}, {"url": "https://git.kernel.org/stable/c/244c442f54601a24c86ad90572bf36fc3df41c5e"}, {"url": "https://git.kernel.org/stable/c/66877a312ae3c2c3d849e82e882f642ffd4ec3e2"}], "title": "tracing: Hold trace_types_lock when updating modules in persistent instances", "x_generator": {"engine": "bippy-1.2.0"}}}}

{}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "Linux", "programFiles": ["kernel/trace/trace.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"lessThan": "57408eac99b0d8a005796346d317d31f0ca4e07a", "status": "affected", "version": "5f3719f697c3fdfae5cd6805f10ac7a04b0f4e43", "versionType": "git"}, {"lessThan": "dab2bd4d67ad5eaa95019a9511f8d379401b5021", "status": "affected", "version": "5f3719f697c3fdfae5cd6805f10ac7a04b0f4e43", "versionType": "git"}, {"lessThan": "244c442f54601a24c86ad90572bf36fc3df41c5e", "status": "affected", "version": "5f3719f697c3fdfae5cd6805f10ac7a04b0f4e43", "versionType": "git"}, {"lessThan": "66877a312ae3c2c3d849e82e882f642ffd4ec3e2", "status": "affected", "version": "5f3719f697c3fdfae5cd6805f10ac7a04b0f4e43", "versionType": "git"}]}, {"defaultStatus": "affected", "product": "Linux", "programFiles": ["kernel/trace/trace.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"status": "affected", "version": "6.15"}, {"lessThan": "6.15", "status": "unaffected", "version": "0", "versionType": "semver"}, {"lessThanOrEqual": "6.18.*", "status": "unaffected", "version": "6.18.60", "versionType": "semver"}, {"lessThanOrEqual": "7.2.*", "status": "unaffected", "version": "7.2.14", "versionType": "semver"}, {"lessThanOrEqual": "7.3.*", "status": "unaffected", "version": "7.3.1", "versionType": "semver"}, {"lessThanOrEqual": "*", "status": "unaffected", "version": "7.4-rc1", "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\ntracing: Hold trace_types_lock when updating modules in persistent instances\n\ntrace_module_record() walks ftrace_trace_arrays from the module notifier\nwithout trace_types_lock. A concurrent rmdir of an instance removes it\nfrom the list and frees it under that lock, so a module load or unload\ncan walk into a freed trace_array."}], "id": "CVE-2026-99238", "lastModified": "2026-11-03T20:18:30.147", "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": "2026-11-02T16:17:49.380", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/244c442f54601a24c86ad90572bf36fc3df41c5e"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/57408eac99b0d8a005796346d317d31f0ca4e07a"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/66877a312ae3c2c3d849e82e882f642ffd4ec3e2"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/dab2bd4d67ad5eaa95019a9511f8d379401b5021"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Received"}

{"bugzilla": {"description": "kernel: kernel: Privilege escalation via use-after-free in tracing subsystem", "id": "2565250", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2565250"}, "csaw": false, "cvss3": {"cvss3_base_score": "7.8", "cvss3_scoring_vector": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "status": "draft"}, "cwe": "CWE-825", "details": ["A flaw was found in the Linux kernel's tracing subsystem. A local attacker could exploit this vulnerability to achieve privilege escalation or cause a Denial of Service (DoS) by crashing the system. The issue is caused by a race condition where module records are updated without acquiring the proper lock during module loading or unloading. This missing synchronization allows a concurrently removed tracing instance to be accessed after being freed, resulting in a use-after-free condition."], "mitigation": {"lang": "en:us", "value": "--- CME Mitigation Guidance (2026-11-04) ---\nDisclaimer: The following mitigation solutions are provided as a courtesy, pending the application of an official patch. This content was generated utilizing AI tools in conjunction with data from https://cmetaxonomy.org. Customers are advised to independently evaluate and test these temporary mitigations within their own infrastructure.\nThe highest-value action is to acquire trace_types_lock before traversing ftrace_trace_arrays in trace_module_record during module loading or unloading: upgrade to the fixed release, which acquire trace_types_lock with a mutex guard before iterating over ftrace_trace_arrays in trace_module_record(), closing concurrent tracefs instance removal during module loading or unloading. Until patched, this is only a concern on Linux systems where local authenticated users can modify tracefs directory structures and trigger module loading or unloading \u2014 Non-Linux operating systems are unaffected \u2014 so Restrict write permissions to tracefs hierarchy directories, drop CAP_SYS_ADMIN, and restrict dynamic kernel module loading and unloading. As a compensating measure, audit syscalls targeting tracefs directory removal and module loading events, detect anomalous privilege escalation and tracing manipulation using eBPF probes, detect kernel use-after-free memory dereferences with runtime memory error detection, enforce non-executable permissions on kernel heap structures using the NX/XD bit, randomize kernel code locations with KASLR to hinder control-flow redirection, and prevent kernel execution of userspace code during privilege escalation via SMEP. These controls limit blast radius and contain exploitation, but they do not fix the underlying use-after-free race condition defect \u2014 apply the upstream patch to fully remediate.\nHighest-impact CME: CME-107 Kernel Module Loading Restriction (high)"}, "name": "CVE-2026-99238", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Not 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"}, {"cpe": "cpe:/a:redhat:openshift:4", "fix_state": "Not affected", "package_name": "openshift/ose-rhel-coreos-8", "product_name": "Red Hat OpenShift Container Platform 4"}, {"cpe": "cpe:/a:redhat:openshift:4", "fix_state": "Not affected", "package_name": "openshift/ose-rhel-coreos-9", "product_name": "Red Hat OpenShift Container Platform 4"}, {"cpe": "cpe:/a:redhat:openshift:5", "fix_state": "Not affected", "package_name": "openshift/ose-rhel-coreos-10", "product_name": "Red Hat OpenShift Container Platform 5"}, {"cpe": "cpe:/a:redhat:openshift:5", "fix_state": "Not affected", "package_name": "openshift/ose-rhel-coreos-9", "product_name": "Red Hat OpenShift Container Platform 5"}], "public_date": "2026-11-02T16:06:42Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-99238\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-99238\nhttps://git.kernel.org/stable/c/244c442f54601a24c86ad90572bf36fc3df41c5e\nhttps://git.kernel.org/stable/c/57408eac99b0d8a005796346d317d31f0ca4e07a\nhttps://git.kernel.org/stable/c/dab2bd4d67ad5eaa95019a9511f8d379401b5021"], "statement": "This vulnerability is rated as Important severity because an attacker with local access who can manage tracing instances can exploit a race condition during dynamic module events to trigger memory corruption, potentially escalating privileges to the kernel level or causing a system crash. In standard Red Hat Enterprise Linux deployments, access to the tracefs hierarchy is restricted to privileged administrators by default, which substantially limits the exposure to non-root users. The flaw specifically requires write permissions to create and delete directory structures within the tracing instances pseudo-filesystem.", "threat_severity": "Important"}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[5f3719f697c3fdfae5cd6805f10ac7a04b0f4e43,57408eac99b0d8a005796346d317d31f0ca4e07a)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[5f3719f697c3fdfae5cd6805f10ac7a04b0f4e43,dab2bd4d67ad5eaa95019a9511f8d379401b5021)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[5f3719f697c3fdfae5cd6805f10ac7a04b0f4e43,244c442f54601a24c86ad90572bf36fc3df41c5e)"}}], "enrichment": {"confidence": 100.0, "confidence_source": "matching", "scores": [{"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux", "vendor": "linux"}, {"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "generic", "value": "6.15"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[0,6.15)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[6.18.60,6.19.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[7.2.14,7.3.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[7.3.1,7.4.0)"}}], "enrichment": {"confidence": 100.0, "confidence_source": "matching", "scores": [{"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux", "vendor": "linux"}, {"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[5f3719f697c3fdfae5cd6805f10ac7a04b0f4e43,57408eac99b0d8a005796346d317d31f0ca4e07a)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[5f3719f697c3fdfae5cd6805f10ac7a04b0f4e43,dab2bd4d67ad5eaa95019a9511f8d379401b5021)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[5f3719f697c3fdfae5cd6805f10ac7a04b0f4e43,244c442f54601a24c86ad90572bf36fc3df41c5e)"}}], "enrichment": {"confidence": 100.0, "confidence_source": "matching", "scores": [{"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": "6.15"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[0,6.15)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[6.18.60,6.19.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[7.2.14,7.3.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[7.3.1,7.4.0)"}}], "enrichment": {"confidence": 100.0, "confidence_source": "matching", "scores": [{"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux_kernel", "vendor": "linux"}], "created": "2026-11-02T18:30:17.733033+00:00", "updated": "2026-11-05T04:15:05.070423+00:00", "vendors": ["linux", "linux$PRODUCT$linux", "linux$PRODUCT$linux_kernel"]}