{"id":"CVE-2026-99110","revision":"af7c2b6abf5249308005126a03ef8495","records":[{"revision":"af7c2b6abf5249308005126a03ef8495","observedAt":"2026-10-31T13:33:50.447+00:00","statement":{"source":"cve-program","id":"CVE-2026-99110","aliases":[],"title":"smb: client: fix heap overflow in cifs_do_set_acl()","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nsmb: client: fix heap overflow in cifs_do_set_acl()\n\ncifs_set_acl() validates ACL size using posix_acl_xattr_size():\n\n        4 + (count * 8)  // 4-byte header + 8 bytes per ACE\n\ncifs_do_set_acl() then calls posix_acl_to_cifs() to write the CIFS\nwire format into the same buffer:\n\n        6 + (count * 10)  // 6-byte header + 10 bytes per ACE\n\nAn ACL that passes the xattr-based check in cifs_set_acl() can\noverflow the heap when posix_acl_to_cifs() writes the larger CIFS\nformat.\n\nValidate the CIFS format size against the remaining buffer space and\nUSHRT_MAX before converting--data_count is __u16, so sizes above\nUSHRT_MAX truncate the on-wire packet length, causing the server to\napply a partial ACL.  Replace MaxDataCount = 1000 with\nmin(CIFSMaxBufSize, USHRT_MAX).","state":0,"publishedAt":"2026-10-28T10:34:28.239+00:00","modifiedAt":"2026-10-31T12:43:03.377+00:00","affected":[{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"unaffected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"fs/smb/client/cifssmb.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"dc1af4c4b4721abfa07b351063825acc7e69cc66\",\n                            \"lessThan\": \"68652afb9b9adf70125971abee9b95341e042249\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"dc1af4c4b4721abfa07b351063825acc7e69cc66\",\n                            \"lessThan\": \"9312a00215602ba028495ef3fa00fb84af0478e0\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"dc1af4c4b4721abfa07b351063825acc7e69cc66\",\n                            \"lessThan\": \"d96f3365ce61c5f39602955af43c8174548dee98\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"dc1af4c4b4721abfa07b351063825acc7e69cc66\",\n                            \"lessThan\": \"596b4062e6c75bdd85a7f2b7f2087a872dc420ac\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"dc1af4c4b4721abfa07b351063825acc7e69cc66\",\n                            \"lessThan\": \"1dac61e2c29d1a71784604b48cf3b1234a65ec29\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        }\n                    ]\n                }"},{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"affected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"fs/smb/client/cifssmb.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"6.2\",\n                            \"status\": \"affected\"\n                        },\n                        {\n                            \"version\": \"0\",\n                            \"lessThan\": \"6.2\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.6.161\",\n                            \"lessThanOrEqual\": \"6.6.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.12.115\",\n                            \"lessThanOrEqual\": \"6.12.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.18.59\",\n                            \"lessThanOrEqual\": \"6.18.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.2.13\",\n                            \"lessThanOrEqual\": \"7.2.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.3\",\n                            \"lessThanOrEqual\": \"*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"original_commit_for_fix\"\n                        }\n                    ]\n                }"}],"metrics":[{"system":"CVSS 3.1","vector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H","score":7,"severity":"HIGH"}],"references":["https://git.kernel.org/stable/c/68652afb9b9adf70125971abee9b95341e042249","https://git.kernel.org/stable/c/9312a00215602ba028495ef3fa00fb84af0478e0","https://git.kernel.org/stable/c/d96f3365ce61c5f39602955af43c8174548dee98","https://git.kernel.org/stable/c/596b4062e6c75bdd85a7f2b7f2087a872dc420ac","https://git.kernel.org/stable/c/1dac61e2c29d1a71784604b48cf3b1234a65ec29"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-99110","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-99110","identifiers":["CVE-2026-99110"]},"retained":false,"historicalAffected":[]}],"coverage":[]}