Use of Uninitialized Variable in Linux kernel - CVE-2026-98935
Published: October 23, 2026
Vulnerability identifier: #VU157572
CSH Severity: Low
CVSS v4: 4.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-98935
CWE-ID: CWE-457
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a local user to disclose uninitialized kernel stack data.
The vulnerability exists due to uninitialized padding in the struct rtc_wkalrm structure in rtc_dev_ioctl() when handling RTC_WKALRM_RD ioctl requests. A local user can issue this ioctl to obtain a structure containing residual kernel stack data in padding bytes after the pending member.
Affected software
Linux kernel
How to mitigate CVE-2026-98935
Install security update from vendor's repository.
Linux kernel - update to 7.0 rc3
External References
- https://git.kernel.org/stable/c/00dc50cede96738dadc64b20e671186cddb8a58d
- https://git.kernel.org/stable/c/0ee5c5d804d592a8328a425b9274487d393d3a05
- https://git.kernel.org/stable/c/2838d7bbb551861c25187dfb581ed6e7a56762e9
- https://git.kernel.org/stable/c/a2215eb3cbbd3d9d73cc18c08e3ef53f903443cb
- https://git.kernel.org/stable/c/beda3c9730ad3087d01aa1d0415c40942042ec87