CVE-2026-98826 Linux CVE debrief

Who should care

Defenders responsible for Linux kernel-based systems, especially those using the affected versions, should assess exposure and prioritize patching. They must verify and apply patches, review and update Linux kernel versions, and monitor systems for potential exploitation attempts. Security teams should conduct thorough vulnerability assessments to identify potential exposure and implement compensating controls for exposed systems. Additionally, defenders,

Why it matters

This vulnerability requires defenders to verify and apply patches, review and update Linux kernel versions, and monitor systems for potential exploitation attempts.

• Verify and apply patches to prevent potential use-after-free exploitation
• Review and update Linux kernel versions to ensure they are not affected
• Monitor systems for potential exploitation attempts

Technical summary

The Linux kernel's rtc: ac100 driver has a use-after-free vulnerability when probe fails. The ac100_rtc_register_clks() function registers the RTC-32k clock and clock provider, but these are not device managed and are only released from ac100_rtc_remove(). If probe() fails after clock registration, the provider remains on the global of_clk_providers list, holding chip->clk_data, which is freed during probe() unwind. This can cause a later lookup to read freed memory in of_clk_hw_onecell_get().

Defensive priority

Defenders should prioritize verifying and applying patches for this vulnerability, especially for systems using the affected Linux kernel versions.

Recommended defensive actions

• Verify and apply patches for this vulnerability
• Review and update Linux kernel versions to ensure they are not affected
• Monitor systems for potential exploitation attempts
• Perform thorough vulnerability assessments to identify potential exposure
• Implement compensating controls for exposed systems
• Conduct regular security audits to detect potential vulnerabilities
• Track and analyze exploitation attempts to improve defenses

Evidence notes

The CVE record and source item provide details on the vulnerability, including its description and affected versions. However, the corpus does not establish specific exploitation or impact, requiring verification from official sources.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.