CVE-2026-98935 — rtc: dev: zero-initialize struct rtc_wkalrm to prevent information leak
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')
Who exploits it and how urgent it is
A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.
How the score was calculated
- EPSS 0.2% (30-day exploitation probability)+1
The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.
Remediation
Fixes and mitigations documented by the sources — linked to the original advisory.
No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.
First 24 hours
Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.
- Identify exposed assets running the affected vendor/product/version combinations (Linux Linux).
- No fix documented in the sources: reduce exposure and monitor the vendor advisory.
- Search available logs for exploit probes, errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
| Vendor | Product | Versions | Status | Source |
|---|---|---|---|---|
| Linux | Linux | ≥ 36e14f5fdfdf7cec8887b7ff69cd9bb5051ecf62 and < a2215eb3cbbd3d9d73cc18c08e3ef53f903443cb≥ 36e14f5fdfdf7cec8887b7ff69cd9bb5051ecf62 and < beda3c9730ad3087d01aa1d0415c40942042ec87≥ 36e14f5fdfdf7cec8887b7ff69cd9bb5051ecf62 and < 00dc50cede96738dadc64b20e671186cddb8a58d≥ 36e14f5fdfdf7cec8887b7ff69cd9bb5051ecf62 and < 2838d7bbb551861c25187dfb581ed6e7a56762e9≥ 36e14f5fdfdf7cec8887b7ff69cd9bb5051ecf62 and < 0ee5c5d804d592a8328a425b9274487d393d3a05version 5.0≥ 36e14f5fdfdf7cec8887b7ff69cd9bb5051ecf62 and < f84eb9b7b0feeb267a174237d70a857042ce0158 | Vulnerable | CVE Program (cve.org) e CISA ADP |
EPSS over time FIRST
Oct 24, 2026 → Oct 30, 2026 · 7 reading(s) · max 0.21%
Detection
Read off the CVSS vector and the weakness class. Starting points, not tested rules.
- Not enough vector or weakness data: use the affected application’s logs as a starting point.
Timeline
What happened to this CVE, newest first.
- 2026
- Affected products added · linux/linux
- Record published
- Affected products added · linux/linux
- Source status changed · → Received
- Record created in this database
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 3× References added · Oct 23, 2026 – Oct 30, 2026
- 1× Official description updated · Oct 23, 2026 – Oct 23, 2026
References
8 on the record
- git.kernel.org/stable/c/a2215eb3cbbd3d9d73cc18c08e3ef53f903443cb
- git.kernel.org/stable/c/0ee5c5d804d592a8328a425b9274487d393d3a05
- git.kernel.org/stable/c/2838d7bbb551861c25187dfb581ed6e7a56762e9
- git.kernel.org/stable/c/00dc50cede96738dadc64b20e671186cddb8a58d
- nvd.nist.gov/vuln/detail/CVE-2026-98935
- git.kernel.org/stable/c/f84eb9b7b0feeb267a174237d70a857042ce0158
- git.kernel.org/stable/c/beda3c9730ad3087d01aa1d0415c40942042ec87
- github.com/advisories/GHSA-p9j5-gjf3-cch6
Elsewhere on this site
Related CVEs (same products)
- Unknown CVE-2026-99216 Drivers: hv: Don't reset VMBus connection state on error/exit paths 2d
- Unknown CVE-2026-99215 power: supply: core: prevent unregistering a power supply while a callback runs 2d
- Unknown CVE-2026-99207 scsi: target: Disable interrupts while holding delayed_cmd_lock 2d
- Unknown CVE-2026-99208 drm/xe/oa: Zero OA buffer at allocation 2d
- Unknown CVE-2026-99209 drm/xe: skip eviction of a BO with no resource 2d
- Unknown CVE-2026-99210 accel/rocket: clear rdev on device init failure 2d
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No CVSS score published by NVD, the CNA, CISA or GitHub so far.
- No fixed version, patch or mitigation documented.
- No CISA SSVC assessment.
- No CWE classification.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.
Answered from this record
Text assembled only from the fields above — no additional claims.
What should defenders know first?
CVE-2026-98935 is "rtc: dev: zero-initialize struct rtc_wkalrm to prevent information leak", rated Unknown. It affects Linux (Linux); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. EPSS 0.18% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.
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