CVE-2026-64390Patch(linux / linux_kernel)

LOWCVSS 8.8 · HIGH

Signal is active with 1 mentions in latest observed window

Immediate actions

  • Patch linux linux_kernel systems immediately

Recommended action window: Monitor and triage in normal cycle

NVD description

In the Linux kernel, the following vulnerability has been resolved: ksmbd: track the connection owning a byte-range lock SMB2_LOCK adds each granted byte-range lock to both the file lock list and the lock list of the connection which handled the request. The final close and durable handle paths, however, remove the connection list entry while holding fp->conn->llist_lock. With SMB3 multichannel, the connection handling the LOCK request can be different from the connection which opened the file. The entry can therefore be removed under a different spinlock from the one protecting the list it belongs to. A concurrent traversal can then access freed struct ksmbd_lock and struct file_lock objects. Record the connection owning each lock's clist entry and hold a reference to it while the entry is linked. Use that connection and its llist_lock for unlock, rollback, close, and durable preserve. Durable reconnect assigns the new connection as the owner when publishing the locks again.

0.5/ 10 priority

Sources & remediation

Priority

LOW

Exploitation

NONE

PoC

NONE

Patch

AVAILABLE

Momentum

NONE

Are you affected?

If you run products in this scope, you should treat this CVE as relevant to your environment.

  • linux_kernel

Threat summary

  • Patch or workaround signal is available
  • 1 mentions across 1 observed day

What's happening

  • Patch or workaround mentioned in 1 signal
  • Technical details provided in 1 signal
  • 1 total mentions across 1 day

Affected systems

Vendors
Products
linux_kernel

Deep dive

Activity timeline1 mentions / 1d
00111Mentions · 2026-09-04: 1Patch / Workaround · 2026-09-04: 1Technical Details · 2026-09-04: 109-04
Signal classification1 categories
Patch
1100.0%
Full discourse1 post
  • DFIR Lab@DFIR_Lab
    Patch

    #HIGH: CVE-2026-64390 in Linux kernel ksmbd (CVSS 8.8). Use-after-free in SMB3 multichannel byte-range lock handling can lead to memory corruption. Patch immediately. #CVE #Vulnerability #PatchNow https://t.co/KGgjYIpHYu

    Post summary

    The tweet warns of a high‑severity use‑after‑free vulnerability in Linux kernel ksmbd (CVE‑2026‑64390, CVSS 8.8) and urges urgent patching; no PoC, exploit, or active exploitation is reported.

    0000047
    124 followersView on X
CPE platform detail1 entries

1 of 1 entries

PartVendorProductVersionTarget SWTarget HW
OSlinuxlinux_kernel---

Explore more