Race condition in Linux kernel - CVE-2026-98449

Vulnerability identifier: #VU156747

CSH Severity: Low

CVSS v4: 2 [CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-98449

CWE-ID: CWE-362

Exploitation vector: Local access

Exploit availability: No public exploit available

The vulnerability allows a local user to cause incorrect SMB credit accounting, potentially disrupting SMB client operation.

The vulnerability exists due to a race condition in the Linux kernel SMB client's compound_send_recv() function when handling a compound request send failure during reconnection. A local user can trigger a socket send failure during a compound request to leave pending request entries accessible to reconnect callbacks, causing both the callbacks and the send-error path to return the same credits and decrement the in_flight counter twice.

Linux kernel
Ubuntu
linux (Ubuntu package)
linux-aws (Ubuntu package)
linux-gcp (Ubuntu package)
linux-oracle (Ubuntu package)
linux-ibm (Ubuntu package)
linux-hwe-7.0 (Ubuntu package)
linux-oem-7.0 (Ubuntu package)

Install security update from vendor's repository.

Linux kernel - update to 7.0 rc3
linux (Ubuntu package) - update to 7.0.0-42.42
linux-aws (Ubuntu package) - update to 7.0.0-1016.17
linux-gcp (Ubuntu package) - update to 7.0.0-1016.18
linux-oracle (Ubuntu package) - update to 7.0.0-1015.16
linux-ibm (Ubuntu package) - update to 7.0.0-1017.17
linux-hwe-7.0 (Ubuntu package) - update to 7.0.0-42.42~24.04.1
linux-oem-7.0 (Ubuntu package) - update to 7.0.0-1017.17

• https://git.kernel.org/stable/c/70783946f3b5d0c06ec7df0f5e7bec2bfad24efb
• https://git.kernel.org/stable/c/8f6f8a48399f82f4a83f7b9f25b9707e0062a4f9

• Race condition in Linux kernel smb client
• Ubuntu update for linux-oem-7.0
• Ubuntu update for linux, linux-aws, linux-gcp and more