CVE-2026-61353: Windows Telephony Service Elevation of Privilege Vulnerability

highCVSS 7.8CVE-2026-61353

Heap-based buffer overflow in Windows Telephony Service allows an authorized attacker to elevate privileges locally.

CSIRTS triage

vendor: Microsoft product: Windows Telephony Service Privilege escalation Memory corruption

What: Heap-based buffer overflow in Windows Telephony Service allows local privilege escalation by an authorized attacker.
Who is affected: Windows systems with Telephony Service enabled where an authorized local user is present.
Urgency: High severity (CVSS 7.8) but not currently exploited; should be patched promptly in the next security update cycle.
Action: Apply Windows security updates when available from Microsoft.

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: high — CVSS 7.8
Published: 2026-08-11
Exploitation: Not in CISA KEV at last sync

Original advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-61353

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-2026-613530.31% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 23% of all EPSS-scored CVEs.

Referenced CVEs

CVE	CSIRTS overview	External
CVE-2026-61353	coverage & exploitation status	NVD · CVE.org

Same CVEs, other sources

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

Recent advisories for Windows Telephony Service

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.

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highCVE-2026-62732: Heap-based buffer overflow in Windows Telephony Service allows an authorized attacker to eleva…nvd · 2026-08-11
highCVE-2026-62729: Concurrent execution using shared resource with improper synchronization ('race condition') in…nvd · 2026-08-11
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