{"id":"CVE-2026-72382","title":"ksmbd: reject undersized DACLs before parsing ACEs","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nksmbd: reject undersized DACLs before parsing ACEs\n\nparse_dacl() limits the attacker-controlled ACE count by comparing it\nwith the number of minimal ACEs that fit in th…","severity":"high","cvss":8.8,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","cvssSource":"cna","vendor":"Linux","product":"Linux","affected":["Linux >= e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 < 8dc949061e35427433feac3ebe5ec089f2aa857e","Linux >= e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 < 16fb65ec15fe7c90f50a2115854bfd9a032d4023","Linux >= e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 < 282847c0cf22f2e961155ac8e42f6eeab7e16049","Linux >= e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 < d020e7f27bf65eecd3805404702f716b2b6d9e73","Linux >= e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 < 15a9e9b8f7f5d7f380ae54c6f5bcbc0bdcb0f3cd","Linux >= e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 < 60908f7ebcd9b6cde74ad5711fab0f49c7970949","Linux 5.15"],"published":"2026-08-15","updated":"2026-10-30","sourceUpdated":"2026-10-30T12:29:13.532Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-72382","references":[{"url":"https://git.kernel.org/stable/c/8dc949061e35427433feac3ebe5ec089f2aa857e"},{"url":"https://git.kernel.org/stable/c/16fb65ec15fe7c90f50a2115854bfd9a032d4023"},{"url":"https://git.kernel.org/stable/c/282847c0cf22f2e961155ac8e42f6eeab7e16049"},{"url":"https://git.kernel.org/stable/c/d020e7f27bf65eecd3805404702f716b2b6d9e73"},{"url":"https://git.kernel.org/stable/c/15a9e9b8f7f5d7f380ae54c6f5bcbc0bdcb0f3cd"},{"url":"https://git.kernel.org/stable/c/60908f7ebcd9b6cde74ad5711fab0f49c7970949"}],"tags":["cve.org"],"epss":0.0068,"epssPercentile":0.52667,"ingestedAt":"2026-11-05T15:02:32.509Z","slug":"CVE-2026-72382","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nksmbd: reject undersized DACLs before parsing ACEs\n\nparse_dacl() limits the attacker-controlled ACE count by comparing it\nwith the number of minimal ACEs that fit in the DACL size. The DACL size\nfield is 16 bits, but the expression subtracts sizeof(struct smb_acl).\nBecause sizeof() is unsigned, a DACL size smaller than the ACL header\nunderflows to a large size_t.\n\nA malicious client can reach this with:\n\nSMB2_SET_INFO (InfoType=SMB2_O_INFO_SECURITY)\n  -> smb2_set_info_sec()\n  -> set_info_sec()\n  -> parse_sec_desc()\n  -> parse_dacl()\n     -> init_acl_state(..., 0xffff)\n     -> init_acl_state(..., 0xffff)\n     -> kmalloc_objs(..., 0xffff)\n\nThus a malformed security descriptor can make num_aces pass the guard\nand drive large temporary ACL state and pointer-array allocations.\n\nReject DACLs smaller than struct smb_acl before doing the subtraction,\nso the ACE count check cannot be bypassed by the underflow.\n\n## Affected\n\n- `Linux >= e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 < 8dc949061e35427433feac3ebe5ec089f2aa857e`\n- `Linux >= e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 < 16fb65ec15fe7c90f50a2115854bfd9a032d4023`\n- `Linux >= e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 < 282847c0cf22f2e961155ac8e42f6eeab7e16049`\n- `Linux >= e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 < d020e7f27bf65eecd3805404702f716b2b6d9e73`\n- `Linux >= e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 < 15a9e9b8f7f5d7f380ae54c6f5bcbc0bdcb0f3cd`\n- `Linux >= e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 < 60908f7ebcd9b6cde74ad5711fab0f49c7970949`\n- `Linux 5.15`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":49,"depthScoreParts":{"impact":48.4,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}