Answer in brief
CVE-2026-68100 records a High severity (CVSS 8.1) vulnerability in ksmbd: validate num_subauth when copying ACE in set_ntacl_dacl. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic), Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 8.1. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Linux/Linux (generic), Linux/Linux (generic), Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <e31fada5143784bc05c7ae44c79eed9b7a2e147e || >=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <fb3dc8e6da46a1ccad1956cda57de29d9b3033e0 || >=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <b6d3cc6a524416dfdb2b47e4bba2e7e20011d056 || >=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <5acbd3012fd4a7ccfebd91ea6f784120084eb897 || >=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <47f0b34f6bc98ed85bfdc293e8f3e432ec24958d || >=0 <6.6.148 || >=0 <6.12.101 || >=0 <6.18.42 || >=0 <7.1.6 | e31fada5143784bc05c7ae44c79eed9b7a2e147e, fb3dc8e6da46a1ccad1956cda57de29d9b3033e0, b6d3cc6a524416dfdb2b47e4bba2e7e20011d056, 5acbd3012fd4a7ccfebd91ea6f784120084eb897, 47f0b34f6bc98ed85bfdc293e8f3e432ec24958d, 6.6.148, 6.12.101, 6.18.42, 7.1.6 |
| Linux/Linuxgeneric | >=e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 <e31fada5143784bc05c7ae44c79eed9b7a2e147e || >=e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 <fb3dc8e6da46a1ccad1956cda57de29d9b3033e0 || >=e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 <b6d3cc6a524416dfdb2b47e4bba2e7e20011d056 || >=e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 <5acbd3012fd4a7ccfebd91ea6f784120084eb897 || >=e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 <47f0b34f6bc98ed85bfdc293e8f3e432ec24958d | e31fada5143784bc05c7ae44c79eed9b7a2e147e, fb3dc8e6da46a1ccad1956cda57de29d9b3033e0, b6d3cc6a524416dfdb2b47e4bba2e7e20011d056, 5acbd3012fd4a7ccfebd91ea6f784120084eb897, 47f0b34f6bc98ed85bfdc293e8f3e432ec24958d |
| Linux/Linuxgeneric | 5.15 | Not reported |
| Linux/Linuxgeneric | >=e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 <26cb845e22a00c85bf566337417fa33492395f10 || >=e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 <e31fada5143784bc05c7ae44c79eed9b7a2e147e || >=e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 <fb3dc8e6da46a1ccad1956cda57de29d9b3033e0 || >=e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 <b6d3cc6a524416dfdb2b47e4bba2e7e20011d056 || >=e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 <5acbd3012fd4a7ccfebd91ea6f784120084eb897 || >=e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 <47f0b34f6bc98ed85bfdc293e8f3e432ec24958d | 26cb845e22a00c85bf566337417fa33492395f10, e31fada5143784bc05c7ae44c79eed9b7a2e147e, fb3dc8e6da46a1ccad1956cda57de29d9b3033e0, b6d3cc6a524416dfdb2b47e4bba2e7e20011d056, 5acbd3012fd4a7ccfebd91ea6f784120084eb897, 47f0b34f6bc98ed85bfdc293e8f3e432ec24958d |
Published upstream
Aug 10, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Aug 23, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 10, 2026
In the Linux kernel, the following vulnerability has been resolved: ksmbd: validate num_subauth when copying ACE in set_ntacl_dacl set_ntacl_dacl() copies each ACE from the attacker-controlled stored security descriptor verbatim into the response DACL without checking sid.num_subauth. The ACE bytes (including an unchecked num_subauth) originate from an authenticated SMB2_SET_INFO(SecInfo=DACL) that is stored raw via ksmbd_vfs_set_sd_xattr(); parse_dacl() rejects a bad ACE with `break` rather than an error, so parse_sec_desc() still returns success and the malformed SD reaches the xattr intact. On a subsequent SMB2_QUERY_INFO(SecInfo=DACL) for an inode carrying a POSIX access ACL, build_sec_desc() -> set_ntacl_dacl() -> set_posix_acl_entries_dacl() walks the copied ACEs and reads ntace->sid.sub_auth[ntace->sid.num_subauth - 1] with num_subauth taken straight from the stored SD. Since sub_auth[] is fixed at SID_MAX_SUB_AUTHORITIES (15), a crafted num_subauth (e.g. 255) drives an out-of-bounds heap read of ~1 KB with an offset fully controlled by an authenticated client. The sibling functions already gate this field: parse_dacl() -- num_subauth == 0 || > SID_MAX_SUB_AUTHORITIES parse_sid() -- num_subauth > SID_MAX_SUB_AUTHORITIES smb_copy_sid() -- min_t(u8, num_subauth, SID_MAX_SUB_AUTHORITIES) set_ntacl_dacl() is the lone inconsistent path that omits the check. Add the same num_subauth validation in set_ntacl_dacl() before copying the ACE, matching the gate already enforced by parse_dacl().
Quoted source text, attributed separately from HOL analysis.