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Full vulnerability report · 2026
CVE-2026-61353High confidence

Windows Telephony Service Elevation of Privilege Vulnerability

Microsoft · Windows 10 Version 1607

7.8HighCVSS 3.1
Recommended action
Within 7 days

High technical severity; prioritise exposed affected systems while verifying vendor guidance.

Patch available
Optional official sources

National CERT insights
?CERT means Computer Emergency Response Team; CSIRT is the closely related term Computer Security Incident Response Team.

Select the national-authority views to include. The exact source language is shown on each matched advisory. Your choice is remembered on this device and encoded in the shareable URL.

Official European source

ENISA European Vulnerability Database

Official EUVD identifiers, advisory evidence and known-exploited context. Missing fields are not treated as evidence of low risk.

1 current
ENISA EUVD identifier

EUVD-2026-56320

No EUVD known-exploited evidence

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

EUVD state
Present in the current official mapping
Known exploitation
Not present in the current ENISA EUVD known-exploited dataset. This is not proof of no exploitation.
ENISA score
7.8 · CVSS 3.1
Advisory evidence
No linked advisory details stored yet
Recommended actionWithin 7 days

High technical severity; prioritise exposed affected systems while verifying vendor guidance.

Patch available
01

What, why and how

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

What

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

Why

A heap overflow condition is a buffer overflow, where the buffer that can be overwritten is allocated in the heap portion of memory, generally meaning that the buffer was allocated using a routine such as malloc().

How

An attacker operating through local access may attempt exploitation with low privileges. If successful, the issue may gain additional privileges.

What

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

Why

A heap overflow condition is a buffer overflow, where the buffer that can be overwritten is allocated in the heap portion of memory, generally meaning that the buffer was allocated using a routine such as malloc().

How

An attacker operating through local access may attempt exploitation with low privileges. If successful, the issue may gain additional privileges.

02

Exploit reality and attack path

CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.

Observed exploitation
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
No confirmed evidence

No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.

Public PoC / exploit material
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
None recorded

No exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.

Likely attack path
local access → Heap-based Buffer Overflow → gain additional privileges
Attack surface
Local
Privileges required
Low: a basic authenticated account is required
User interaction
None
Attack complexity
Low: no specialised conditions are recorded
Security boundary
Unchanged: impact remains within the vulnerable component's security authority
Weakness
?CWE means Common Weakness Enumeration: a standard category for the underlying weakness.
CWE-122 ↗

CWE-122: Heap-based Buffer Overflow. A heap overflow condition is a buffer overflow, where the buffer that can be overwritten is allocated in the heap portion of memory, generally meaning that the buffer was allocated using a routine such as malloc().

CVSS vector
?CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity.
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C

Common Vulnerability Scoring System 3.1: the compact vector below is decoded into plain language.

AVLocalAttack vector: The attacker needs local access to the vulnerable system.ACLowAttack complexity: No specialised conditions are required beyond attacker-controlled input.PRLowPrivileges required: The attacker needs basic user-level privileges.UINoneUser interaction: No action by another user is required.SUnchangedScope: The security impact remains within the vulnerable component's authority.CHighConfidentiality impact: A successful attack can cause a major loss.IHighIntegrity impact: A successful attack can cause a major loss.AHighAvailability impact: A successful attack can cause a major loss.
Post-exploitation / living off the land
The issue can support a local privilege or sandbox boundary transition; normal system utilities may then be available in the gained context.
Privilege escalationCWE-122
A

Official authority intelligence

Only matched European and national findings are included. Language selectors and unavailable sources are omitted.

ENISA EUVD · EUVD-2026-56320Official EUVD mapping

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

Official EUVD record
BSI · German · WID-SEC-W-2026-2756Microsoft Windows Produkte: Mehrere Schwachstellen

Ein Angreifer kann mehrere Schwachstellen in Microsoft Windows Server 2012, Microsoft Windows Server 2012 R2, Microsoft Windows Server 2016, Microsoft Windows 10, Microsoft Windows Server 2019, Microsoft Windows Server 2022, Microsoft Exchange, Microsoft Windows 11, Microsoft Windows Server 2025 und Microsoft Windows ausnutzen, um beliebigen Programmcode auszuführen, um seine Privilegien zu erhöhen, um einen Denial of Service Angriff durchzuführen, um Informationen offenzulegen, um Dateien zu manipulieren, um einen Cross-Site Scripting Angriff durchzuführen, und um Sicherheitsvorkehrungen zu umgehen.

Official advisory
CERT-FR · French · CERTFR-2026-AVI-1001Multiples vulnérabilités dans Microsoft Windows

é Microsoft Windows CVE-2026-59137 du 11 août 2026 Bulletin de sécurité Microsoft Windows CVE-2026-59138 du 11 août 2026 Bulletin de sécurité Microsoft Windows CVE-2026-61345 du 11 août 2026 Bulletin de sécurité Microsoft Windows CVE-2026-61346 du 11 août 2026 Bulletin de sécurité Microsoft Windows CVE-2026-61347 du 11 août 2026 Bulletin de sécurité Microsoft Windows CVE-2026-61348 du 11 août 2026 Bulletin de sécurité Microsoft Windows CVE-2026-61349 du 11 août 2026 Bulletin de sécurité Microsoft Windows CVE-2026-61350 du 11 août 2026 Bulletin de sécurité Microsoft Windows CVE-2026-61352 du 11 août 2026 Bulletin de sécurité Microsoft Windows CVE-2026-61353 du 11 août 2026 Bulletin de sécurité Microsoft Windows CVE-2026-61355 du 11 août 2026 Bulletin de sécurité Microsoft Windows CVE-2026-61356 du 11 août 2026 Bulletin de sécurité Microsoft Windows CVE-2026-61357 du 11 août 2026 Bulletin de sécurité Microsoft Windows CVE-2026-61358 du 11 août 2026 Bulletin de sécurité Microsoft Windows CVE-2026-61359 du 11 août 2026 Bulletin de sécurité Microsoft Windows CVE-2026-61360 du 11 août 2026 Bulletin de sécurité Microsoft Windows CVE-2026-61361 du 11 août 2026 Bulletin de sécurité Microsoft Windows CVE-2026-61363 du 11 août 2026 Bulletin de sécurité Microsoft Windows CVE-2026-61364 du 11 août 2026 Bul

Official advisory
CSIRT Italia · Italian · aggiornamenti-mensili-microsoft-23Aggiornamenti Mensili Microsoft

nuova finestra - - CVE-2026-61918 : apre una nuova finestra - - CVE-2026-61368 : apre una nuova finestra - - CVE-2026-61367 : apre una nuova finestra - - CVE-2026-61366 : apre una nuova finestra - - CVE-2026-61365 : apre una nuova finestra - - CVE-2026-61364 : apre una nuova finestra - - CVE-2026-61363 : apre una nuova finestra - - CVE-2026-61361 : apre una nuova finestra - - CVE-2026-61360 : apre una nuova finestra - - CVE-2026-61359 : apre una nuova finestra - - CVE-2026-61358 : apre una nuova finestra - - CVE-2026-61357 : apre una nuova finestra - - CVE-2026-61356 : apre una nuova finestra - - CVE-2026-61355 : apre una nuova finestra - - CVE-2026-61353 : apre una nuova finestra - - CVE-2026-61352 : apre una nuova finestra - - CVE-2026-61350 : apre una nuova finestra - - CVE-2026-61349 : apre una nuova finestra - - CVE-2026-61348 : apre una nuova finestra - - CVE-2026-61347 : apre una nuova finestra - - CVE-2026-61346 : apre una nuova finestra - - CVE-2026-61345 : apre una nuova finestra - - CVE-2026-59138 : apre una nuova finestra - - CVE-2026-59137 : apre una nuova finestra - - CVE-2026-59136 : apre una nuova finestra - - CVE-2026-59135 : apre una nuova finestra - - CVE-2026-59134 : apre una nuova finestra - - CVE-2026-59133 : apre una nuova finestra - - CVE-2026-59132 : apre una nuova fi

Official advisory
NCSC-NL · Dutch · NCSC-2026-0284Kwetsbaarheden verholpen in Microsoft Windows

A heap-based buffer overflow vulnerability in the Windows Telephony Service allows an authorized local attacker to elevate privileges on the affected system.

Official advisory
03

Patch and workaround

Operational remediation based on structured source evidence.

Status
?Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change.
Patch available
Affected
10.0.14393.0 < 10.0.14393.9418; 10.0.17763.0 < 10.0.17763.9121; 10.0.19044.0 < 10.0.19044.7663; 10.0.19045.0 < 10.0.19045.7663; 10.0.22631.0 < 10.0.22631.7517; 10.0.26100.0 < 10.0.26100.9168; 10.0.26200.0 < 10.0.26200.9168
Fixed
An authoritative update reference is available, but the fixed version is not recorded in the structured CVE fields. Check the linked vendor advisory for the applicable release.
Action
Review the linked authoritative reference and apply the recorded fixed release appropriate to the affected product branch.
Workaround
No verified workaround is recorded. Limit untrusted access and use least privilege until authoritative guidance is available.
04

Evidence and provenance

Published 11 Aug 2026 · Last source change 3 Sept 2026, 21:22 UTC · CWE-122 · Heap-based Buffer Overflow

CVE recordCVE.org · 5.2
CVSS sourceCNA
EPSS source
?The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.
FIRST · tracked since 2026-08-14
European sourceENISA EUVD · EUVD-2026-56320
Product sourceCNA
Remediation sourceCVE/CNA references
CWE sourceOther authority
NVD statusNVD enriched

Core structured fields are present and their contributing authorities are shown above.

Material change intelligence

What changed after publication

View recent updates →
  1. Affected versionsThe structured affected or fixed version information changed.
    Before
    10.0.14393.0 < 10.0.14393.9418; 10.0.17763.0 < 10.0.17763.9115; 10.0.19044.0 < 10.0.19044.7663; 10.0.19045.0 < 10.0.19045.7663; 10.0.22631.0 < 10.0.22631.7517; 10.0.26100.0 < 10.0.26100.9168; 10.0.26200.0 < 10.0.26200.9168 · Fixed: An authoritative update reference is available, but the fixed version is not recorded in the structured CVE fields. Check the linked vendor advisory for the applicable release.
    After
    10.0.14393.0 < 10.0.14393.9418; 10.0.17763.0 < 10.0.17763.9121; 10.0.19044.0 < 10.0.19044.7663; 10.0.19045.0 < 10.0.19045.7663; 10.0.22631.0 < 10.0.22631.7517; 10.0.26100.0 < 10.0.26100.9168; 10.0.26200.0 < 10.0.26200.9168 · Fixed: An authoritative update reference is available, but the fixed version is not recorded in the structured CVE fields. Check the linked vendor advisory for the applicable release.
    CNA ↗
Material fields only · duplicate refreshes suppressed · history retained for the configured operational retention period
CVE published
Fixed release or patch reference recorded
ENISA EUVD · EUVD-2026-56320↗CVE authority or vendor reference↗Official CVE record (CNA and ADP data)↗NVD record↗
Technical terms and abbreviations used in this report
CVE
Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
CVSS
Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
EPSS
Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
CWE
Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
CNA
CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
CISA ADP
Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
NVD
National Vulnerability Database: NIST's enrichment service for CVE records.
CERT / CSIRT
A computer security incident response team that publishes warnings or coordinates incident response.
PoC
Proof of concept: public material that demonstrates or helps reproduce exploitation.
CSAF
Common Security Advisory Framework: a machine-readable format for security advisories.
LoTL
Living off the land: abuse of legitimate tools or system functions during an attack.
Free version - for non-commercial use only.CVE-2026-61353 · cve.blacktree.nl