CVE-2026-23327

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-23327", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-01-13T15:37:45.996Z", "datePublished": "2026-03-25T10:27:19.815Z", "dateUpdated": "2026-11-05T21:33:38.949Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-30T12:23:55.930Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ncxl/mbox: validate payload size before accessing contents in cxl_payload_from_user_allowed()\n\ncxl_payload_from_user_allowed() casts and dereferences the input\npayload without first verifying its size. When a raw mailbox command\nis sent with an undersized payload (ie: 1 byte for CXL_MBOX_OP_CLEAR_LOG,\nwhich expects a 16-byte UUID), uuid_equal() reads past the allocated buffer,\ntriggering a KASAN splat:\n\nBUG: KASAN: slab-out-of-bounds in memcmp+0x176/0x1d0 lib/string.c:683\nRead of size 8 at addr ffff88810130f5c0 by task syz.1.62/2258\n\nCPU: 2 UID: 0 PID: 2258 Comm: syz.1.62 Not tainted 6.19.0-dirty #3 PREEMPT(voluntary)\nHardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.17.0-0-gb52ca86e094d-prebuilt.qemu.org 04/01/2014\nCall Trace:\n <TASK>\n __dump_stack lib/dump_stack.c:94 [inline]\n dump_stack_lvl+0xab/0xe0 lib/dump_stack.c:120\n print_address_description mm/kasan/report.c:378 [inline]\n print_report+0xce/0x650 mm/kasan/report.c:482\n kasan_report+0xce/0x100 mm/kasan/report.c:595\n memcmp+0x176/0x1d0 lib/string.c:683\n uuid_equal include/linux/uuid.h:73 [inline]\n cxl_payload_from_user_allowed drivers/cxl/core/mbox.c:345 [inline]\n cxl_mbox_cmd_ctor drivers/cxl/core/mbox.c:368 [inline]\n cxl_validate_cmd_from_user drivers/cxl/core/mbox.c:522 [inline]\n cxl_send_cmd+0x9c0/0xb50 drivers/cxl/core/mbox.c:643\n __cxl_memdev_ioctl drivers/cxl/core/memdev.c:698 [inline]\n cxl_memdev_ioctl+0x14f/0x190 drivers/cxl/core/memdev.c:713\n vfs_ioctl fs/ioctl.c:51 [inline]\n __do_sys_ioctl fs/ioctl.c:597 [inline]\n __se_sys_ioctl fs/ioctl.c:583 [inline]\n __x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583\n do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]\n do_syscall_64+0xa8/0x330 arch/x86/entry/syscall_64.c:94\n entry_SYSCALL_64_after_hwframe+0x77/0x7f\nRIP: 0033:0x7fdaf331ba79\nCode: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48\nRSP: 002b:00007fdaf1d77038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010\nRAX: ffffffffffffffda RBX: 00007fdaf3585fa0 RCX: 00007fdaf331ba79\nRDX: 00002000000001c0 RSI: 00000000c030ce02 RDI: 0000000000000003\nRBP: 00007fdaf33749df R08: 0000000000000000 R09: 0000000000000000\nR10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000\nR13: 00007fdaf3586038 R14: 00007fdaf3585fa0 R15: 00007ffced2af768\n </TASK>\n\nAdd 'in_size' parameter to cxl_payload_from_user_allowed() and validate\nthe payload is large enough."}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["drivers/cxl/core/mbox.c"], "versions": [{"version": "6179045ccc0c6229dc449afc1701dc7fbd40571f", "lessThan": "c0874ca9282ccf5aeae559c697dd1feb577aad0e", "status": "affected", "versionType": "git"}, {"version": "6179045ccc0c6229dc449afc1701dc7fbd40571f", "lessThan": "3555e41737c0f8b5b53a511573661477e3942dee", "status": "affected", "versionType": "git"}, {"version": "6179045ccc0c6229dc449afc1701dc7fbd40571f", "lessThan": "483b7eb4b1b2a03235afe1b274732dcf8231d4ec", "status": "affected", "versionType": "git"}, {"version": "6179045ccc0c6229dc449afc1701dc7fbd40571f", "lessThan": "dc184ac2f0ba77ae19725ee06ad3ab36bb9d1f61", "status": "affected", "versionType": "git"}, {"version": "6179045ccc0c6229dc449afc1701dc7fbd40571f", "lessThan": "7c8a7b7f063b7e7ae9bba4cbaa14a5d2fe3a55e1", "status": "affected", "versionType": "git"}, {"version": "6179045ccc0c6229dc449afc1701dc7fbd40571f", "lessThan": "60b5d1f68338aff2c5af0113f04aefa7169c50c2", "status": "affected", "versionType": "git"}]}, {"product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["drivers/cxl/core/mbox.c"], "versions": [{"version": "5.19", "status": "affected"}, {"version": "0", "lessThan": "5.19", "status": "unaffected", "versionType": "semver"}, {"version": "6.1.191", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.6.160", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.12.114", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.18.34", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.19.7", "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": "5.19", "versionEndExcluding": "6.1.191"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.19", "versionEndExcluding": "6.6.160"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.19", "versionEndExcluding": "6.12.114"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.19", "versionEndExcluding": "6.18.34"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.19", "versionEndExcluding": "6.19.7"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.19", "versionEndExcluding": "7.0"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/c0874ca9282ccf5aeae559c697dd1feb577aad0e"}, {"url": "https://git.kernel.org/stable/c/3555e41737c0f8b5b53a511573661477e3942dee"}, {"url": "https://git.kernel.org/stable/c/483b7eb4b1b2a03235afe1b274732dcf8231d4ec"}, {"url": "https://git.kernel.org/stable/c/dc184ac2f0ba77ae19725ee06ad3ab36bb9d1f61"}, {"url": "https://git.kernel.org/stable/c/7c8a7b7f063b7e7ae9bba4cbaa14a5d2fe3a55e1"}, {"url": "https://git.kernel.org/stable/c/60b5d1f68338aff2c5af0113f04aefa7169c50c2"}], "title": "cxl/mbox: validate payload size before accessing contents in cxl_payload_from_user_allowed()", "x_generator": {"engine": "bippy-1.2.0"}}, "adp": [{"metrics": [{"other": {"type": "ssvc", "content": {"id": "CVE-2026-23327", "role": "CISA Coordinator", "options": [{"Exploitation": "none"}, {"Automatable": "no"}, {"Technical Impact": "partial"}], "version": "2.0.3", "timestamp": "2026-11-05T21:26:57.683069Z"}}}], "title": "CISA ADP Vulnrichment", "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-11-05T21:33:38.949Z"}}]}}

{"dataType": "CVE_RECORD", "containers": {"adp": [{"title": "CISA ADP Vulnrichment", "metrics": [{"other": {"type": "ssvc", "content": {"id": "CVE-2026-23327", "role": "CISA Coordinator", "options": [{"Exploitation": "none"}, {"Automatable": "no"}, {"Technical Impact": "partial"}], "version": "2.0.3", "timestamp": "2026-11-05T21:26:57.683069Z"}}}], "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-11-05T21:26:58.659Z"}}], "cna": {"title": "cxl/mbox: validate payload size before accessing contents in cxl_payload_from_user_allowed()", "affected": [{"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "product": "Linux", "versions": [{"status": "affected", "version": "6179045ccc0c6229dc449afc1701dc7fbd40571f", "lessThan": "c0874ca9282ccf5aeae559c697dd1feb577aad0e", "versionType": "git"}, {"status": "affected", "version": "6179045ccc0c6229dc449afc1701dc7fbd40571f", "lessThan": "3555e41737c0f8b5b53a511573661477e3942dee", "versionType": "git"}, {"status": "affected", "version": "6179045ccc0c6229dc449afc1701dc7fbd40571f", "lessThan": "483b7eb4b1b2a03235afe1b274732dcf8231d4ec", "versionType": "git"}, {"status": "affected", "version": "6179045ccc0c6229dc449afc1701dc7fbd40571f", "lessThan": "dc184ac2f0ba77ae19725ee06ad3ab36bb9d1f61", "versionType": "git"}, {"status": "affected", "version": "6179045ccc0c6229dc449afc1701dc7fbd40571f", "lessThan": "7c8a7b7f063b7e7ae9bba4cbaa14a5d2fe3a55e1", "versionType": "git"}, {"status": "affected", "version": "6179045ccc0c6229dc449afc1701dc7fbd40571f", "lessThan": "60b5d1f68338aff2c5af0113f04aefa7169c50c2", "versionType": "git"}], "programFiles": ["drivers/cxl/core/mbox.c"], "defaultStatus": "unaffected"}, {"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "product": "Linux", "versions": [{"status": "affected", "version": "5.19"}, {"status": "unaffected", "version": "0", "lessThan": "5.19", "versionType": "semver"}, {"status": "unaffected", "version": "6.1.191", "versionType": "semver", "lessThanOrEqual": "6.1.*"}, {"status": "unaffected", "version": "6.6.160", "versionType": "semver", "lessThanOrEqual": "6.6.*"}, {"status": "unaffected", "version": "6.12.114", "versionType": "semver", "lessThanOrEqual": "6.12.*"}, {"status": "unaffected", "version": "6.18.34", "versionType": "semver", "lessThanOrEqual": "6.18.*"}, {"status": "unaffected", "version": "6.19.7", "versionType": "semver", "lessThanOrEqual": "6.19.*"}, {"status": "unaffected", "version": "7.0", "versionType": "original_commit_for_fix", "lessThanOrEqual": "*"}], "programFiles": ["drivers/cxl/core/mbox.c"], "defaultStatus": "affected"}], "references": [{"url": "https://git.kernel.org/stable/c/c0874ca9282ccf5aeae559c697dd1feb577aad0e"}, {"url": "https://git.kernel.org/stable/c/3555e41737c0f8b5b53a511573661477e3942dee"}, {"url": "https://git.kernel.org/stable/c/483b7eb4b1b2a03235afe1b274732dcf8231d4ec"}, {"url": "https://git.kernel.org/stable/c/dc184ac2f0ba77ae19725ee06ad3ab36bb9d1f61"}, {"url": "https://git.kernel.org/stable/c/7c8a7b7f063b7e7ae9bba4cbaa14a5d2fe3a55e1"}, {"url": "https://git.kernel.org/stable/c/60b5d1f68338aff2c5af0113f04aefa7169c50c2"}], "x_generator": {"engine": "bippy-1.2.0"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ncxl/mbox: validate payload size before accessing contents in cxl_payload_from_user_allowed()\n\ncxl_payload_from_user_allowed() casts and dereferences the input\npayload without first verifying its size. When a raw mailbox command\nis sent with an undersized payload (ie: 1 byte for CXL_MBOX_OP_CLEAR_LOG,\nwhich expects a 16-byte UUID), uuid_equal() reads past the allocated buffer,\ntriggering a KASAN splat:\n\nBUG: KASAN: slab-out-of-bounds in memcmp+0x176/0x1d0 lib/string.c:683\nRead of size 8 at addr ffff88810130f5c0 by task syz.1.62/2258\n\nCPU: 2 UID: 0 PID: 2258 Comm: syz.1.62 Not tainted 6.19.0-dirty #3 PREEMPT(voluntary)\nHardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.17.0-0-gb52ca86e094d-prebuilt.qemu.org 04/01/2014\nCall Trace:\n <TASK>\n __dump_stack lib/dump_stack.c:94 [inline]\n dump_stack_lvl+0xab/0xe0 lib/dump_stack.c:120\n print_address_description mm/kasan/report.c:378 [inline]\n print_report+0xce/0x650 mm/kasan/report.c:482\n kasan_report+0xce/0x100 mm/kasan/report.c:595\n memcmp+0x176/0x1d0 lib/string.c:683\n uuid_equal include/linux/uuid.h:73 [inline]\n cxl_payload_from_user_allowed drivers/cxl/core/mbox.c:345 [inline]\n cxl_mbox_cmd_ctor drivers/cxl/core/mbox.c:368 [inline]\n cxl_validate_cmd_from_user drivers/cxl/core/mbox.c:522 [inline]\n cxl_send_cmd+0x9c0/0xb50 drivers/cxl/core/mbox.c:643\n __cxl_memdev_ioctl drivers/cxl/core/memdev.c:698 [inline]\n cxl_memdev_ioctl+0x14f/0x190 drivers/cxl/core/memdev.c:713\n vfs_ioctl fs/ioctl.c:51 [inline]\n __do_sys_ioctl fs/ioctl.c:597 [inline]\n __se_sys_ioctl fs/ioctl.c:583 [inline]\n __x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583\n do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]\n do_syscall_64+0xa8/0x330 arch/x86/entry/syscall_64.c:94\n entry_SYSCALL_64_after_hwframe+0x77/0x7f\nRIP: 0033:0x7fdaf331ba79\nCode: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48\nRSP: 002b:00007fdaf1d77038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010\nRAX: ffffffffffffffda RBX: 00007fdaf3585fa0 RCX: 00007fdaf331ba79\nRDX: 00002000000001c0 RSI: 00000000c030ce02 RDI: 0000000000000003\nRBP: 00007fdaf33749df R08: 0000000000000000 R09: 0000000000000000\nR10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000\nR13: 00007fdaf3586038 R14: 00007fdaf3585fa0 R15: 00007ffced2af768\n </TASK>\n\nAdd 'in_size' parameter to cxl_payload_from_user_allowed() and validate\nthe payload is large enough."}], "cpeApplicability": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "6.1.191", "versionStartIncluding": "5.19"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "6.6.160", "versionStartIncluding": "5.19"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "6.12.114", "versionStartIncluding": "5.19"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "6.18.34", "versionStartIncluding": "5.19"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "6.19.7", "versionStartIncluding": "5.19"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "7.0", "versionStartIncluding": "5.19"}], "operator": "OR"}]}], "providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-30T12:23:55.930Z"}}}, "cveMetadata": {"cveId": "CVE-2026-23327", "state": "PUBLISHED", "dateUpdated": "2026-11-05T21:33:38.949Z", "dateReserved": "2026-01-13T15:37:45.996Z", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "datePublished": "2026-03-25T10:27:19.815Z", "assignerShortName": "Linux"}, "dataVersion": "5.2"}

{"affected": [{"affectedData": [{"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": "c0874ca9282ccf5aeae559c697dd1feb577aad0e", "status": "affected", "version": "6179045ccc0c6229dc449afc1701dc7fbd40571f", "versionType": "git"}, {"lessThan": "3555e41737c0f8b5b53a511573661477e3942dee", "status": "affected", "version": "6179045ccc0c6229dc449afc1701dc7fbd40571f", "versionType": "git"}, {"lessThan": "483b7eb4b1b2a03235afe1b274732dcf8231d4ec", "status": "affected", "version": "6179045ccc0c6229dc449afc1701dc7fbd40571f", "versionType": "git"}, {"lessThan": "dc184ac2f0ba77ae19725ee06ad3ab36bb9d1f61", "status": "affected", "version": "6179045ccc0c6229dc449afc1701dc7fbd40571f", "versionType": "git"}, {"lessThan": "7c8a7b7f063b7e7ae9bba4cbaa14a5d2fe3a55e1", "status": "affected", "version": "6179045ccc0c6229dc449afc1701dc7fbd40571f", "versionType": "git"}, {"lessThan": "60b5d1f68338aff2c5af0113f04aefa7169c50c2", "status": "affected", "version": "6179045ccc0c6229dc449afc1701dc7fbd40571f", "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": "5.19"}, {"lessThan": "5.19", "status": "unaffected", "version": "0", "versionType": "semver"}, {"lessThanOrEqual": "6.1.*", "status": "unaffected", "version": "6.1.191", "versionType": "semver"}, {"lessThanOrEqual": "6.6.*", "status": "unaffected", "version": "6.6.160", "versionType": "semver"}, {"lessThanOrEqual": "6.12.*", "status": "unaffected", "version": "6.12.114", "versionType": "semver"}, {"lessThanOrEqual": "6.18.*", "status": "unaffected", "version": "6.18.34", "versionType": "semver"}, {"lessThanOrEqual": "6.19.*", "status": "unaffected", "version": "6.19.7", "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": "74C0D01A-385D-4859-8FCC-93ACC7B4B847", "versionEndExcluding": "6.19.7", "versionStartIncluding": "5.19.1", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:5.19:-:*:*:*:*:*:*", "matchCriteriaId": "9D759CCF-9E1B-41B2-81AA-CB580C5F3EEC", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc1:*:*:*:*:*:*", "matchCriteriaId": "F253B622-8837-4245-BCE5-A7BF8FC76A16", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc2:*:*:*:*:*:*", "matchCriteriaId": "4AE85AD8-4641-4E7C-A2F4-305E2CD9EE64", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc3:*:*:*:*:*:*", "matchCriteriaId": "F666C8D8-6538-46D4-B318-87610DE64C34", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc4:*:*:*:*:*:*", "matchCriteriaId": "02259FDA-961B-47BC-AE7F-93D7EC6E90C2", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc5:*:*:*:*:*:*", "matchCriteriaId": "58A9FEFF-C040-420D-8F0A-BFDAAA1DF258", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc6:*:*:*:*:*:*", "matchCriteriaId": "1D2315C0-D46F-4F85-9754-F9E5E11374A6", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc7:*:*:*:*:*:*", "matchCriteriaId": "512EE3A8-A590-4501-9A94-5D4B268D6138", "vulnerable": true}], "negate": false, "operator": "OR"}]}], "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ncxl/mbox: validate payload size before accessing contents in cxl_payload_from_user_allowed()\n\ncxl_payload_from_user_allowed() casts and dereferences the input\npayload without first verifying its size. When a raw mailbox command\nis sent with an undersized payload (ie: 1 byte for CXL_MBOX_OP_CLEAR_LOG,\nwhich expects a 16-byte UUID), uuid_equal() reads past the allocated buffer,\ntriggering a KASAN splat:\n\nBUG: KASAN: slab-out-of-bounds in memcmp+0x176/0x1d0 lib/string.c:683\nRead of size 8 at addr ffff88810130f5c0 by task syz.1.62/2258\n\nCPU: 2 UID: 0 PID: 2258 Comm: syz.1.62 Not tainted 6.19.0-dirty #3 PREEMPT(voluntary)\nHardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.17.0-0-gb52ca86e094d-prebuilt.qemu.org 04/01/2014\nCall Trace:\n <TASK>\n __dump_stack lib/dump_stack.c:94 [inline]\n dump_stack_lvl+0xab/0xe0 lib/dump_stack.c:120\n print_address_description mm/kasan/report.c:378 [inline]\n print_report+0xce/0x650 mm/kasan/report.c:482\n kasan_report+0xce/0x100 mm/kasan/report.c:595\n memcmp+0x176/0x1d0 lib/string.c:683\n uuid_equal include/linux/uuid.h:73 [inline]\n cxl_payload_from_user_allowed drivers/cxl/core/mbox.c:345 [inline]\n cxl_mbox_cmd_ctor drivers/cxl/core/mbox.c:368 [inline]\n cxl_validate_cmd_from_user drivers/cxl/core/mbox.c:522 [inline]\n cxl_send_cmd+0x9c0/0xb50 drivers/cxl/core/mbox.c:643\n __cxl_memdev_ioctl drivers/cxl/core/memdev.c:698 [inline]\n cxl_memdev_ioctl+0x14f/0x190 drivers/cxl/core/memdev.c:713\n vfs_ioctl fs/ioctl.c:51 [inline]\n __do_sys_ioctl fs/ioctl.c:597 [inline]\n __se_sys_ioctl fs/ioctl.c:583 [inline]\n __x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583\n do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]\n do_syscall_64+0xa8/0x330 arch/x86/entry/syscall_64.c:94\n entry_SYSCALL_64_after_hwframe+0x77/0x7f\nRIP: 0033:0x7fdaf331ba79\nCode: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48\nRSP: 002b:00007fdaf1d77038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010\nRAX: ffffffffffffffda RBX: 00007fdaf3585fa0 RCX: 00007fdaf331ba79\nRDX: 00002000000001c0 RSI: 00000000c030ce02 RDI: 0000000000000003\nRBP: 00007fdaf33749df R08: 0000000000000000 R09: 0000000000000000\nR10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000\nR13: 00007fdaf3586038 R14: 00007fdaf3585fa0 R15: 00007ffced2af768\n </TASK>\n\nAdd 'in_size' parameter to cxl_payload_from_user_allowed() and validate\nthe payload is large enough."}, {"lang": "es", "value": "En el kernel de Linux, la siguiente vulnerabilidad ha sido resuelta:\n\ncxl/mbox: validar el tama\u00f1o de la carga \u00fatil antes de acceder a los contenidos en cxl_payload_from_user_allowed()\n\ncxl_payload_from_user_allowed() convierte y desreferencia la carga \u00fatil de entrada sin verificar primero su tama\u00f1o. Cuando se env\u00eda un comando de buz\u00f3n sin procesar con una carga \u00fatil de tama\u00f1o insuficiente (es decir: 1 byte para CXL_MBOX_OP_CLEAR_LOG, que espera un UUID de 16 bytes), uuid_equal() lee m\u00e1s all\u00e1 del b\u00fafer asignado, lo que activa un KASAN splat:\n\nBUG: KASAN: slab-out-of-bounds en memcmp+0x176/0x1d0 lib/string.c:683\nLectura de tama\u00f1o 8 en la direcci\u00f3n ffff88810130f5c0 por la tarea syz.1.62/2258\n\nCPU: 2 UID: 0 PID: 2258 Comm: syz.1.62 No contaminado 6.19.0-dirty #3 PREEMPT(voluntary)\nNombre del hardware: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.17.0-0-gb52ca86e094d-prebuilt.qemu.org 04/01/2014\nTraza de llamadas:\n \n __dump_stack lib/dump_stack.c:94 [inline]\n dump_stack_lvl+0xab/0xe0 lib/dump_stack.c:120\n print_address_description mm/kasan/report.c:378 [inline]\n print_report+0xce/0x650 mm/kasan/report.c:482\n kasan_report+0xce/0x100 mm/kasan/report.c:595\n memcmp+0x176/0x1d0 lib/string.c:683\n uuid_equal include/linux/uuid.h:73 [inline]\n cxl_payload_from_user_allowed drivers/cxl/core/mbox.c:345 [inline]\n cxl_mbox_cmd_ctor drivers/cxl/core/mbox.c:368 [inline]\n cxl_validate_cmd_from_user drivers/cxl/core/mbox.c:522 [inline]\n cxl_send_cmd+0x9c0/0xb50 drivers/cxl/core/mbox.c:643\n __cxl_memdev_ioctl drivers/cxl/core/memdev.c:698 [inline]\n cxl_memdev_ioctl+0x14f/0x190 drivers/cxl/core/memdev.c:713\n vfs_ioctl fs/ioctl.c:51 [inline]\n __do_sys_ioctl fs/ioctl.c:597 [inline]\n __se_sys_ioctl fs/ioctl.c:583 [inline]\n __x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583\n do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]\n do_syscall_64+0xa8/0x330 arch/x86/entry/syscall_64.c:94\n entry_SYSCALL_64_after_hwframe+0x77/0x7f\nRIP: 0033:0x7fdaf331ba79\nCode: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 &lt;48&gt; 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48\nRSP: 002b:00007fdaf1d77038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010\nRAX: ffffffffffffffda RBX: 00007fdaf3585fa0 RCX: 00007fdaf331ba79\nRDX: 00002000000001c0 RSI: 00000000c030ce02 RDI: 0000000000000003\nRBP: 00007fdaf33749df R08: 0000000000000000 R09: 0000000000000000\nR10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000\nR13: 00007fdaf3586038 R14: 00007fdaf3585fa0 R15: 00007ffced2af768\n \n\nA\u00f1adir el par\u00e1metro 'in_size' a cxl_payload_from_user_allowed() y validar que la carga \u00fatil sea lo suficientemente grande."}], "id": "CVE-2026-23327", "lastModified": "2026-11-05T22:18:15.060", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "LOCAL", "availabilityImpact": "HIGH", "baseScore": 7.1, "baseSeverity": "HIGH", "confidentialityImpact": "HIGH", "integrityImpact": "NONE", "privilegesRequired": "LOW", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H", "version": "3.1"}, "exploitabilityScore": 1.8, "impactScore": 5.2, "source": "nvd@nist.gov", "type": "Primary"}], "ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-23327", "options": [{"exploitation": "none"}, {"automatable": "no"}, {"technicalImpact": "partial"}], "role": "CISA Coordinator", "timestamp": "2026-11-05T21:26:57.683069Z", "version": "2.0.3"}}]}, "published": "2026-03-25T11:16:29.837", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/3555e41737c0f8b5b53a511573661477e3942dee"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/483b7eb4b1b2a03235afe1b274732dcf8231d4ec"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/60b5d1f68338aff2c5af0113f04aefa7169c50c2"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/7c8a7b7f063b7e7ae9bba4cbaa14a5d2fe3a55e1"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/c0874ca9282ccf5aeae559c697dd1feb577aad0e"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/dc184ac2f0ba77ae19725ee06ad3ab36bb9d1f61"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Modified", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-125"}], "source": "nvd@nist.gov", "type": "Primary"}]}

{"bugzilla": {"description": "kernel: cxl/mbox: validate payload size before accessing contents in cxl_payload_from_user_allowed()", "id": "2451279", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2451279"}, "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"}, "details": ["No description is available for this CVE."], "name": "CVE-2026-23327", "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": "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"}], "public_date": "2026-03-25T00:00:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-23327\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-23327\nhttps://lore.kernel.org/linux-cve-announce/2026032532-CVE-2026-23327-c497@gregkh/T"], "threat_severity": "Moderate"}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[6179045ccc0c6229dc449afc1701dc7fbd40571f,7c8a7b7f063b7e7ae9bba4cbaa14a5d2fe3a55e1)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[6179045ccc0c6229dc449afc1701dc7fbd40571f,60b5d1f68338aff2c5af0113f04aefa7169c50c2)"}}], "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": "5.19"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[0,5.19)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.19.7,6.20.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[7.0-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"}], "analysis": {"en": {"generated_at": "2026-04-28T17:16:20.966043+00:00", "value": {"mitigation_remediation": ["Apply the latest kernel update that includes the CVE-2026-23327 fix", "If an upgrade is not feasible, disable the CXL driver or restrict access to /dev/cxl devices", "Monitor system logs for KASAN splats or kernel crashes related to CXL", "Reboot affected systems after a crash to restore stability"], "summary": {"action": "Apply Patch", "impact": "Kernel memory corruption potentially leading to privilege escalation or denial of service"}, "threat_synthesis": {"affected_systems": "The vulnerability affects the Linux kernel, specifically the CXL core mailbox code in drivers/cxl/core/mbox.c. All kernels that include this code and have not applied the recent patch introducing an in_size parameter are potentially affected. The patch addresses the issue in the referenced kernel commits, and the vulnerability was demonstrated against a 6.19.0 kernel in a QEMU test environment. Administrators should verify whether their running kernel contains the fix; any kernel prior to the patch is considered susceptible.", "description_and_impact": "In the Linux kernel's CXL mailbox implementation, the function cxl_payload_from_user_allowed() casts and dereferences an input payload without first ensuring that the payload buffer is large enough. When a raw mailbox command containing an undersized payload is processed\u2014for example, sending a 1-byte payload for the CXL_MBOX_OP_CLEAR_LOG operation that expects a 16-byte UUID\u2014the kernel reads past the end of the buffer. This out-of-bounds read is caught by Kernel Address Sanitizer, producing a KASAN splat that indicates a memory corruption condition. The corruption can potentially allow an attacker to read kernel memory, leading to information disclosure or, if further exploitation is achieved, local privilege escalation or a system crash.", "risk_and_exploitability": "With a CVSS score of 7.1 this vulnerability is considered high severity. The EPSS score is below 1%, indicating low predicted exploitation frequency, and it is not listed in the CISA Known Exploited Vulnerabilities catalog. Attackers likely need access to a CXL device or the ability to invoke ioctl calls on /dev/cxl devices, implying local or privileged access. While the vulnerability can cause a denial of service through a kernel crash, a malicious actor with sufficient privileges could leverage the out-of-bounds read to leak kernel data or potentially bootstrap further privilege\u2011escalation exploits. System availability and kernel integrity are at risk."}}}}, "created": "2026-03-25T21:27:33.972785+00:00", "updated": "2026-04-28T17:30:10.610265+00:00", "vendors": ["linux", "linux$PRODUCT$linux_kernel"], "weaknesses": ["CWE-125", "CWE-20"]}