CVE-2026-45949: hwrng: core - use RCU and work_struct to fix race condition

mediumCVSS 5.5CVE-2026-45949

CSIRTS triage

vendor: Linux product: Linux KernelOther

What: A race condition in the hwrng core driver is fixed by using RCU and work_struct.
Who is affected: Systems running affected Linux kernel versions with hardware random number generators are vulnerable.
Urgency: Medium severity (CVSS 5.5) and not exploited; standard kernel update priority.
Action: Apply a kernel patch that incorporates RCU and work_struct changes to hwrng core.

AI-assisted analysis generated from the source advisory — verify against the original.

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Details

Source: Microsoft Security Response Center (INTL · vendor-psirt · site)
Severity: medium — CVSS 5.5
Published: 2026-08-06
Exploitation: Not in CISA KEV at last sync

Original advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-45949

Exploitation outlook

EPSS (FIRST.org) estimates each CVE’s probability of exploitation in the next 30 days — here is the CSIRTS.com read on those numbers.

Low exploitation riskCVE-2026-459490.09% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 0% of all EPSS-scored CVEs.

Referenced CVEs

CVE	CSIRTS overview	External
CVE-2026-45949	coverage & exploitation status	NVD · CVE.org

Same CVEs, other sources

How other CERTs, PSIRTs and databases cover the vulnerabilities in this advisory.

high[UPDATE] [high] Linux Kernel: Multiple Vulnerabilitiescert-bund

Recent advisories for hwrng

A cluster of recent advisories against the same product widens the attack surface — attackers routinely chain freshly published CVEs on one product, so review these together.

highCVE-2026-64456: hwrng: virtio: clamp device-reported used.len at copy_data()msrc · 2026-08-06
highCVE-2026-64456: In the Linux kernel, the following vulnerability has been resolved: hwrng: virtio: clamp devic…nvd · 2026-07-25