CVE-2026-68098 ksmbd: bound DACL dedup walk to copied ACEs
An out-of-bounds read in the Linux kernel ksmbd module allows attackers to inspect invalid memory or cause a crash during DACL processing.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-68098?
CVE-2026-68098 is a high-severity memory corruption vulnerability in Linux, published on 10 Aug 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
ksmbd: bound DACL dedup walk to copied ACEs
set_ntacl_dacl() can stop copying ACEs before consuming the full input DACL when size accounting overflows.
When that happens, num_aces reflects only the ACEs that were actually copied into the output DACL, but set_posix_acl_entries_dacl() still receives nt_num_aces and uses it to walk the existing ACE array during dedup.
That makes the dedup walk scan past the copied ACE array and inspect buffer tail that does not contain valid ACEs.
Split the two meanings currently carried by the NT ACE count. Pass the number of copied NT ACEs to bound the dedup walk, and preserve the original "input DACL had NT ACEs" state separately for the Everyone/default ACL fallback.
This keeps the dedup walk aligned with the ACEs that are actually present in the rebuilt DACL.
Weakness: CWE-125
Which versions are affected by CVE-2026-68098?
How do I fix CVE-2026-68098?
Apply the vendor's patch.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-68098 being exploited?
There is no known exploitation of CVE-2026-68098 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-68098, DEBIAN-CVE-2026-68098, GHSA-v5fh-ff84-cfpv, UBUNTU-CVE-2026-68098.