Integer overflow in Linux kernel - CVE-2026-98634

Vulnerability identifier: #VU156946

CSH Severity: Low

CVSS v4: 6.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-98634

CWE-ID: CWE-190

Exploitation vector: Local access

Exploit availability: No public exploit available

The vulnerability allows a local user to disrupt kernel zone bookkeeping and potentially cause a denial of service.

The vulnerability exists due to integer truncation and signed integer overflow in the Linux kernel SCSI zoned-disk handling functions sd_zbc_read_zones() and sd_zbc_report_zones() when processing devices reporting excessive zone counts. A local user can supply a device reporting such counts to cause inconsistent zone bookkeeping and potentially a denial of service, because per-zone resources are sized using a truncated count and the signed zone index can overflow past INT_MAX.

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/0af16d8be3ec7ff28bb56a0da79c9aed66ac2c3b
• https://git.kernel.org/stable/c/3ddf8383b54456f19fd73d3cebed81bd250c7388
• https://git.kernel.org/stable/c/b6ec0f79745967c751c85df373062c8d15e45fc4
• https://git.kernel.org/stable/c/d8791ae55d85dfaeafa20ea48365482a0cc5a107

• Integer overflow in Linux kernel scsi driver
• Ubuntu update for linux-oem-7.0
• Ubuntu update for linux, linux-aws, linux-gcp and more