{"api_version":"1","generated_at":"2026-09-29T05:23:54+00:00","cve":"CVE-2026-93186","urls":{"html":"https://cve.report/CVE-2026-93186","api":"https://cve.report/api/cve/CVE-2026-93186.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-93186","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-93186"},"summary":{"title":"cxl/mbox: Clamp mailbox output allocation to the payload size","description":"In the Linux kernel, the following vulnerability has been resolved:\n\ncxl/mbox: Clamp mailbox output allocation to the payload size\n\nCXL_MEM_SEND_COMMAND bounds the user's in.size to the mailbox payload\nsize but leaves out.size unbounded, then cxl_mbox_cmd_ctor() calls\nkvzalloc(out.size). A large out.size drives a huge allocation, above\nINT_MAX it WARNs and taints, and with panic_on_warn=1 it panics.\n\nThe transport __cxl_pci_mbox_send_cmd() already clamps the response copy\nto min(out.size, payload_size, device len), so the output buffer is\nnever written beyond payload_size. Clamp the allocation to payload_size\ntoo, matching the RAW path.","state":"PUBLISHED","assigner":"Linux","published_at":"2026-09-17 17:18:14","updated_at":"2026-09-17 17:18:14"},"problem_types":[],"metrics":[],"references":[{"url":"https://git.kernel.org/stable/c/31d4841eca7c4b75751ca96d24339e19303337f2","name":"https://git.kernel.org/stable/c/31d4841eca7c4b75751ca96d24339e19303337f2","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/b4e11c731d6bee3b87315e055a1ca417c92dc1fc","name":"https://git.kernel.org/stable/c/b4e11c731d6bee3b87315e055a1ca417c92dc1fc","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/8a13db9f899d149c3aab24abcb668121cfda5a4f","name":"https://git.kernel.org/stable/c/8a13db9f899d149c3aab24abcb668121cfda5a4f","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/f5d2bbf0300f46307948864fbb97bce5097f4fe2","name":"https://git.kernel.org/stable/c/f5d2bbf0300f46307948864fbb97bce5097f4fe2","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-93186","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-93186","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 583fa5e71caeb79e04e477e9837e2f7fa53b71e4 f5d2bbf0300f46307948864fbb97bce5097f4fe2 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 583fa5e71caeb79e04e477e9837e2f7fa53b71e4 31d4841eca7c4b75751ca96d24339e19303337f2 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 583fa5e71caeb79e04e477e9837e2f7fa53b71e4 b4e11c731d6bee3b87315e055a1ca417c92dc1fc git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 583fa5e71caeb79e04e477e9837e2f7fa53b71e4 8a13db9f899d149c3aab24abcb668121cfda5a4f git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 5.12","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 5.12 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.12.110 6.12.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.18.52 6.18.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.2.6 7.2.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.3-rc1 * original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":{"cve_year":"2026","cve_id":"93186","cve":"CVE-2026-93186","epss":"0.001860000","percentile":"0.084890000","score_date":"2026-09-19","updated_at":"2026-09-20 00:14:31"},"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","programFiles":["drivers/cxl/core/mbox.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"f5d2bbf0300f46307948864fbb97bce5097f4fe2","status":"affected","version":"583fa5e71caeb79e04e477e9837e2f7fa53b71e4","versionType":"git"},{"lessThan":"31d4841eca7c4b75751ca96d24339e19303337f2","status":"affected","version":"583fa5e71caeb79e04e477e9837e2f7fa53b71e4","versionType":"git"},{"lessThan":"b4e11c731d6bee3b87315e055a1ca417c92dc1fc","status":"affected","version":"583fa5e71caeb79e04e477e9837e2f7fa53b71e4","versionType":"git"},{"lessThan":"8a13db9f899d149c3aab24abcb668121cfda5a4f","status":"affected","version":"583fa5e71caeb79e04e477e9837e2f7fa53b71e4","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["drivers/cxl/core/mbox.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"5.12"},{"lessThan":"5.12","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"6.12.*","status":"unaffected","version":"6.12.110","versionType":"semver"},{"lessThanOrEqual":"6.18.*","status":"unaffected","version":"6.18.52","versionType":"semver"},{"lessThanOrEqual":"7.2.*","status":"unaffected","version":"7.2.6","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"7.3-rc1","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.12.110","versionStartIncluding":"5.12","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.18.52","versionStartIncluding":"5.12","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.2.6","versionStartIncluding":"5.12","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.3-rc1","versionStartIncluding":"5.12","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\ncxl/mbox: Clamp mailbox output allocation to the payload size\n\nCXL_MEM_SEND_COMMAND bounds the user's in.size to the mailbox payload\nsize but leaves out.size unbounded, then cxl_mbox_cmd_ctor() calls\nkvzalloc(out.size). A large out.size drives a huge allocation, above\nINT_MAX it WARNs and taints, and with panic_on_warn=1 it panics.\n\nThe transport __cxl_pci_mbox_send_cmd() already clamps the response copy\nto min(out.size, payload_size, device len), so the output buffer is\nnever written beyond payload_size. Clamp the allocation to payload_size\ntoo, matching the RAW path."}],"providerMetadata":{"dateUpdated":"2026-09-17T16:12:12.121Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/f5d2bbf0300f46307948864fbb97bce5097f4fe2"},{"url":"https://git.kernel.org/stable/c/31d4841eca7c4b75751ca96d24339e19303337f2"},{"url":"https://git.kernel.org/stable/c/b4e11c731d6bee3b87315e055a1ca417c92dc1fc"},{"url":"https://git.kernel.org/stable/c/8a13db9f899d149c3aab24abcb668121cfda5a4f"}],"title":"cxl/mbox: Clamp mailbox output allocation to the payload size","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-93186","datePublished":"2026-09-17T16:12:12.121Z","dateReserved":"2026-09-17T16:02:15.091Z","dateUpdated":"2026-09-17T16:12:12.121Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-09-17 17:18:14","lastModifiedDate":"2026-09-17 17:18:14","problem_types":[],"metrics":[],"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"93186","Ordinal":"1","Title":"cxl/mbox: Clamp mailbox output allocation to the payload size","CVE":"CVE-2026-93186","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"93186","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\ncxl/mbox: Clamp mailbox output allocation to the payload size\n\nCXL_MEM_SEND_COMMAND bounds the user's in.size to the mailbox payload\nsize but leaves out.size unbounded, then cxl_mbox_cmd_ctor() calls\nkvzalloc(out.size). A large out.size drives a huge allocation, above\nINT_MAX it WARNs and taints, and with panic_on_warn=1 it panics.\n\nThe transport __cxl_pci_mbox_send_cmd() already clamps the response copy\nto min(out.size, payload_size, device len), so the output buffer is\nnever written beyond payload_size. Clamp the allocation to payload_size\ntoo, matching the RAW path.","Type":"Description","Title":"cxl/mbox: Clamp mailbox output allocation to the payload size"}]}}}