CVE-2026-74646: misc: fastrpc: take fl->lock when moving mmaps on interrupted invoke

mediumCVSS 5.3CVE-2026-74646

CSIRTS triage

vendor: Linux product: Linux kernel Memory corruption

What: Missing lock acquisition when moving mmaps during interrupted fastrpc invocation can cause concurrent memory modification.
Who is affected: Systems running vulnerable Linux kernel versions with fastrpc miscellaneous driver enabled.
Urgency: Medium priority; not currently exploited but race conditions on mmap lists can cause memory corruption.
Action: Apply kernel patch acquiring fl->lock during mmap relocation in drivers/misc/fastrpc.c or update to patched kernel version.

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 5.3
Published: 2026-08-11
Exploitation: Not in CISA KEV at last sync

Original advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-74646

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-2026-746460.13% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 3% of all EPSS-scored CVEs.

Referenced CVEs

CVE	CSIRTS overview	External
CVE-2026-74646	coverage & exploitation status	NVD · CVE.org

Same CVEs, other sources

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

highCVE-2026-74646: In the Linux kernel, the following vulnerability has been resolved: misc: fastrpc: take fl->lo…nvd

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