CVE-2026-98935: Linux kernel · rtc: dev: zero-initialize struct rtc_wkalrm to prevent information leak
Affects Linux kernelSource GCVE Database
Not known to be exploited.
Data as of 28 Oct 2026, 02:15 UTC
Rated by Threat Radar · CVSS not yet scored by NVD
Exploitation evidence
Disclosed: evidence found.
CVE published 23 Oct 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 26.04 LTSlinuxpkg:deb/ubuntu/linux?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-gkepkg:deb/ubuntu/linux-gke?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
A fix is available that zero-initializes the rtc_wkalrm struct to prevent information leakage. Users should apply the updated Linux kernel versions that include this fix. No additional mitigation steps are indicated.
Description
A vulnerability in the Linux kernel's RTC driver could leak uninitialized kernel stack data to userspace due to padding holes in the rtc_wkalrm structure. This occurs when the structure is returned via the RTC_WKALRM_RD ioctl call. The issue is resolved by zero-initializing the struct to prevent information leakage.
References
- ubuntu.com/security/CVE-2026-98935 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-98935 (opens in a new tab)
- git.kernel.org/stable/c/00dc50cede96738dadc64b20e671186cddb8a58d (opens in a new tab)
- git.kernel.org/stable/c/0ee5c5d804d592a8328a425b9274487d393d3a05 (opens in a new tab)
- git.kernel.org/stable/c/2838d7bbb551861c25187dfb581ed6e7a56762e9 (opens in a new tab)
- git.kernel.org/stable/c/a2215eb3cbbd3d9d73cc18c08e3ef53f903443cb (opens in a new tab)
- git.kernel.org/stable/c/beda3c9730ad3087d01aa1d0415c40942042ec87 (opens in a new tab)