CVE-2026-53161: misc: fastrpc: fix use-after-free of fastrpc_user in workqueue context

highCVSS 7CVE-2026-53161

CSIRTS triage

Other

What: This vulnerability involves a use-after-free issue in fastrpc_user.
Who is affected: Deployments using fastrpc may be affected.
Urgency: Remediation is urgent due to the high severity rating.
Action: Apply the latest patches for fastrpc.

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

Details

Source: Microsoft Security Response Center (INTL · vendor-psirt · site)
Severity: high — CVSS 7
Published: 2026-06-09
Exploitation: Not in CISA KEV at last sync

Original advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-53161

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-2026-531610.13% 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-2026-53161	coverage & exploitation status	NVD · CVE.org

Same CVEs, other sources

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

unknownMultiple vulnerabilities in SUSE Linux kernel (August 21, 2026)cert-fr-avis
unknownMultiple vulnerabilities in SUSE Linux kernel (July 24, 2026)cert-fr-avis
unknownMultiple vulnerabilities in Debian LTS Linux kernel (July 10, 2026)cert-fr-avis
unknownMultiple vulnerabilities in Microsoft Azure Linux (June 29, 2026)cert-fr-avis

Recent advisories for misc

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.

unknownCVE-2026-74681: In the Linux kernel, the following vulnerability has been resolved: usb: misc: usbio: check ib…nvd · 2026-08-22
highCVE-2026-74647: In the Linux kernel, the following vulnerability has been resolved: misc: fastrpc: Remove buff…nvd · 2026-08-22
highCVE-2026-74646: In the Linux kernel, the following vulnerability has been resolved: misc: fastrpc: take fl->lo…nvd · 2026-08-22
unknownCVE-2026-74618: In the Linux kernel, the following vulnerability has been resolved: binfmt_misc: don't warn wh…nvd · 2026-08-22
unknownCVE-2026-74487: In the Linux kernel, the following vulnerability has been resolved: binfmt_misc: restore write…nvd · 2026-08-15
unknownCVE-2026-74486: In the Linux kernel, the following vulnerability has been resolved: binfmt_misc: use exe_file_…nvd · 2026-08-15