{"id":"CVE-2026-64366","state":"PUBLISHED","title":"HID: wacom: fix slab-out-of-bounds write in wacom_wac_queue_insert","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nHID: wacom: fix slab-out-of-bounds write in wacom_wac_queue_insert\n\nwacom_wac_queue_insert() calls kfifo_skip() in a loop when the kfifo\ndoesn't have enough space for the incoming report. If the kfifo is\nempty, kfifo_skip() reads stale data left in the kmalloc'd buffer\nvia __kfifo_peek_n() and interprets it as a record length, advancing\nfifo->out by that garbage value. This corrupts the internal kfifo\nstate, causing kfifo_unused() to return a value much larger than the\nactual buffer size, which bypasses __kfifo_in_r()'s guard:\n\n  if (len + recsize > kfifo_unused(fifo))\n      return 0;\n\nkfifo_copy_in() then performs an out-of-bounds memcpy, writing up to\n3842 bytes past the 256-byte buffer.\n\nAdd a !kfifo_is_empty() condition to the while loop so kfifo_skip()\nis never called on an empty fifo, and check the return value of\nkfifo_in() to reject reports that are too large for the fifo.","publishedAt":"2026-07-25T08:50:20.612Z","updatedAt":"2026-10-19T20:38:24.864Z","severity":{"score":8.8,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"5e013ad206895e72d7da41bc1ae89d8cb499c3aa","status":"affected","lessThan":"ca899a926c11a59211b764b0155d9a1cdcc32b81","versionType":"git"},{"version":"5e013ad206895e72d7da41bc1ae89d8cb499c3aa","status":"affected","lessThan":"57bdd10ad50d68341f500a7b330f0d8949e510ec","versionType":"git"},{"version":"5e013ad206895e72d7da41bc1ae89d8cb499c3aa","status":"affected","lessThan":"6b3014ec0e9a390ca563030b2d7689921f0daef5","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/hid/wacom_sys.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.15","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.15","versionType":"semver"},{"version":"6.18.39","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.4","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/hid/wacom_sys.c"]}],"references":["https://git.kernel.org/stable/c/ca899a926c11a59211b764b0155d9a1cdcc32b81","https://git.kernel.org/stable/c/57bdd10ad50d68341f500a7b330f0d8949e510ec","https://git.kernel.org/stable/c/6b3014ec0e9a390ca563030b2d7689921f0daef5"],"weaknesses":["CWE-787"],"ingestedAt":"2026-10-29T20:12:41.951Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/64xxx/CVE-2026-64366.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-64366","state":"PUBLISHED","datePublished":"2026-07-25T08:50:20.612Z","dateUpdated":"2026-10-19T20:38:24.864Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-07-19T15:36:31.783Z"},"containers":{"cna":{"title":"HID: wacom: fix slab-out-of-bounds write in wacom_wac_queue_insert","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nHID: wacom: fix slab-out-of-bounds write in wacom_wac_queue_insert\n\nwacom_wac_queue_insert() calls kfifo_skip() in a loop when the kfifo\ndoesn't have enough space for the incoming report. If the kfifo is\nempty, kfifo_skip() reads stale data left in the kmalloc'd buffer\nvia __kfifo_peek_n() and interprets it as a record length, advancing\nfifo->out by that garbage value. This corrupts the internal kfifo\nstate, causing kfifo_unused() to return a value much larger than the\nactual buffer size, which bypasses __kfifo_in_r()'s guard:\n\n  if (len + recsize > kfifo_unused(fifo))\n      return 0;\n\nkfifo_copy_in() then performs an out-of-bounds memcpy, writing up to\n3842 bytes past the 256-byte buffer.\n\nAdd a !kfifo_is_empty() condition to the while loop so kfifo_skip()\nis never called on an empty fifo, and check the return value of\nkfifo_in() to reject reports that are too large for the fifo."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"5e013ad206895e72d7da41bc1ae89d8cb499c3aa","status":"affected","lessThan":"ca899a926c11a59211b764b0155d9a1cdcc32b81","versionType":"git"},{"version":"5e013ad206895e72d7da41bc1ae89d8cb499c3aa","status":"affected","lessThan":"57bdd10ad50d68341f500a7b330f0d8949e510ec","versionType":"git"},{"version":"5e013ad206895e72d7da41bc1ae89d8cb499c3aa","status":"affected","lessThan":"6b3014ec0e9a390ca563030b2d7689921f0daef5","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/hid/wacom_sys.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.15","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.15","versionType":"semver"},{"version":"6.18.39","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.4","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/hid/wacom_sys.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/ca899a926c11a59211b764b0155d9a1cdcc32b81"},{"url":"https://git.kernel.org/stable/c/57bdd10ad50d68341f500a7b330f0d8949e510ec"},{"url":"https://git.kernel.org/stable/c/6b3014ec0e9a390ca563030b2d7689921f0daef5"}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","baseScore":8.8,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:A - The Wacom driver accepts Bluetooth HID devices, whose attacker-controlled descriptors and reports reach wacom_raw_event through HIDP or UHID. A malicious peripheral within Bluetooth range can therefore trigger the flaw.\nAC:L - A single oversized crafted report can deterministically corrupt the empty FIFO state and trigger the overwrite. No race or condition outside the attacker's control is required.\nPR:N - A connected malicious Bluetooth peripheral needs no account or kernel capability on the target. The report-processing path contains no privilege or authentication check.\nUI:N - Once the malicious peripheral is connected, it can transmit the triggering report without any concurrent victim action.\nS:U - The corruption occurs inside the host kernel and compromises resources governed by that same security authority; it does not inherently cross a VM or IOMMU boundary.\nC:H - The large attacker-controlled heap overwrite can corrupt adjacent kernel objects and be developed into code-execution or arbitrary-memory-access primitives, exposing kernel and process memory.\nI:H - The report supplies thousands of attacker-controlled bytes beyond a small slab object, enabling corruption of adjacent objects and potential kernel control-flow hijacking.\nA:H - The extensive slab overwrite can immediately cause a kernel oops or panic, and the triggering report can be sent repeatedly."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-17T04:54:14.203Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.15","versionEndExcluding":"6.18.39"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.15","versionEndExcluding":"7.1.4"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.15","versionEndExcluding":"7.2"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2026-64366","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"total"}],"version":"2.0.3","timestamp":"2026-10-16T15:39:29.451436Z"}}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-787","lang":"en","type":"CWE","description":"CWE-787 Out-of-bounds Write"}]}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-19T20:38:24.864Z"}}]}}}