CVE-2026-43376
Published: May 8, 2026· Updated: May 12, 2026
Official Description
In the Linux kernel, the following vulnerability has been resolved:
ksmbd: fix use-after-free by using call_rcu() for oplock_info
ksmbd currently frees oplock_info immediately using kfree(), even
though it is accessed under RCU read-side critical sections in places
like opinfo_get() and proc_show_files().
Since there is no RCU grace period delay between nullifying the pointer
and freeing the memory, a reader can still access oplock_info
structure after it has been freed. This can leads to a use-after-free
especially in opinfo_get() where atomic_inc_not_zero() is called on
already freed memory.
Fix this by switching to deferred freeing using call_rcu().
Technical Analysis
CVE-2026-43376 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.
The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.
A successful exploit results in complete confidentiality breach (data exposure), full integrity compromise (data manipulation), availability disruption (denial of service), with a CVSS base score of 9.8.
CVSS v3.1 Vector Breakdown
Affected Vendors & Products
Exploit & PoC Resources
All References (5)
Quick Facts
Recommended Actions
- →Apply vendor patches immediately
- →Monitor CVE-2026-43376 in threat intel feeds
- →Review IDS/IPS signatures for exploitation attempts