Answer in brief
CVE-2026-31704 records a Unknown severity vulnerability in ksmbd: use check_add_overflow() to prevent u16 DACL size overflow. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic), Siemens/SIMATIC S7-1500 TM MFP - GNU/Linux subsystem (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
A CVSS score is not reported in the current record. 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), Siemens/SIMATIC S7-1500 TM MFP - GNU/Linux subsystem (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 <41e53a773db6342ac9a689ee5ba635c31744c9f0 || >=e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 <8d5729350b236896f51379588d9a690b7fafb8db || >=e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 <e1955a94b6f17f4b058afa955a6f187eb3ed7615 || >=e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 <5e7b8f3c539d69b2ed5f2408e2f75e68ce7eef43 || >=e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 <ef7902be3f215b6bf7babe4dc9dd9a7d57dad7a7 || >=e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 <299f962c0b02d048fb45d248b4da493d03f3175d | 41e53a773db6342ac9a689ee5ba635c31744c9f0, 8d5729350b236896f51379588d9a690b7fafb8db, e1955a94b6f17f4b058afa955a6f187eb3ed7615, 5e7b8f3c539d69b2ed5f2408e2f75e68ce7eef43, ef7902be3f215b6bf7babe4dc9dd9a7d57dad7a7, 299f962c0b02d048fb45d248b4da493d03f3175d |
| Linux/Linuxgeneric | 5.15 | Not reported |
| Siemens/SIMATIC S7-1500 TM MFP - GNU/Linux subsystemgeneric | >=0 <* | * |
Published upstream
May 1, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Oct 15, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Oct 15, 2026
In the Linux kernel, the following vulnerability has been resolved: ksmbd: use check_add_overflow() to prevent u16 DACL size overflow set_posix_acl_entries_dacl() and set_ntacl_dacl() accumulate ACE sizes in u16 variables. When a file has many POSIX ACL entries, the accumulated size can wrap past 65535, causing the pointer arithmetic (char *)pndace + *size to land within already-written ACEs. Subsequent writes then overwrite earlier entries, and pndacl->size gets a truncated value. Use check_add_overflow() at each accumulation point to detect the wrap before it corrupts the buffer, consistent with existing check_mul_overflow() usage elsewhere in smbacl.c.
Quoted source text, attributed separately from HOL analysis.