{"id":"CVE-2026-99110","aliases":[],"title":"smb: client: fix heap overflow in cifs_do_set_acl()","titleSource":"Linux","descriptionSource":"Linux","products":[{"vendor":"Linux","name":"Linux","platforms":[],"versions":[{"version":"dc1af4c4b4721abfa07b351063825acc7e69cc66","status":"affected","lessThan":"d96f3365ce61c5f39602955af43c8174548dee98","versionType":"git"},{"version":"dc1af4c4b4721abfa07b351063825acc7e69cc66","status":"affected","lessThan":"596b4062e6c75bdd85a7f2b7f2087a872dc420ac","versionType":"git"},{"version":"dc1af4c4b4721abfa07b351063825acc7e69cc66","status":"affected","lessThan":"1dac61e2c29d1a71784604b48cf3b1234a65ec29","versionType":"git"}],"defaultStatus":"unaffected","source":"Linux","url":"https://www.cve.org/CVERecord?id=CVE-2026-99110"},{"vendor":"Linux","name":"Linux","platforms":[],"versions":[{"version":"6.2","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.2","versionType":"semver"},{"version":"6.18.59","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.13","status":"unaffected","lessThanOrEqual":"7.2.*","versionType":"semver"},{"version":"7.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"defaultStatus":"affected","source":"Linux","url":"https://www.cve.org/CVERecord?id=CVE-2026-99110"}],"remediation":[],"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).","severity":"unknown","score":null,"published":"2026-10-28T10:34:28.239Z","modified":"2026-10-28T10:34:28.239Z","withdrawn":false,"knownExploited":false,"affected":[],"references":["https://git.kernel.org/stable/c/d96f3365ce61c5f39602955af43c8174548dee98","https://git.kernel.org/stable/c/596b4062e6c75bdd85a7f2b7f2087a872dc420ac","https://git.kernel.org/stable/c/1dac61e2c29d1a71784604b48cf3b1234a65ec29"],"sources":[{"name":"CVE","id":"CVE-2026-99110","modified":"2026-10-28T10:34:28.239Z","url":"https://www.cve.org/CVERecord?id=CVE-2026-99110"}],"assessments":[],"sourceAffected":[],"kev":{"status":"not-listed","checkedAt":"2026-10-29T04:20:33.105Z"},"coverage":[{"source":"NVD","status":"not-checked"},{"source":"GHSA","status":"not-checked"},{"source":"EUVD","status":"not-checked"},{"source":"EPSS","status":"not-checked"}],"evidence":[]}