CVE-2026-45487: Windows Program Compatibility Assistant Service Elevation of Privilege Vulnerability

8

Low

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

No exploitation signal in the sources consulted so far.

How the score was calculated

EPSS 0.2% (30-day exploitation probability)+2
Technical severity (high)+6

The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.

Exploitation

Not confirmed

Not in CISA KEV — an absence of record, not proof it is unexploited.

EPSS FIRST

0.21%

ahead of 11% of scored CVEs · Oct 14, 2026

Affects

Microsoft

Windows 10 21h2 and 14 more

CVSS base

7.0

High · 3 source(s)

Prioritization reference: 7.8 provisional

CISA SSVC assessment CISA

Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.

Exploitation

None

none · proof-of-concept · active

Automatable

No

can an attacker script the kill-chain steps

Technical impact

Total

partial · total control of the vulnerable component

Remediation

Fixes and mitigations documented by the sources — linked to the original advisory.

No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.

First 24 hours

Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.

Identify exposed assets running the affected vendor/product/version combinations (Microsoft Windows 10 21h2, Microsoft Windows 10 22h2, Microsoft Windows 10 Version 21H2…).
No fix documented in the sources: reduce exposure and monitor the vendor advisory.
Search available logs for exploit probes matching the vulnerability class (logic error), errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

Vendor	Product	Versions	Status	Source
Microsoft	Windows 10 21h2	< 10.0.19044.7417	Vulnerable	NIST National Vulnerability Database
Microsoft	Windows 10 22h2	< 10.0.19045.7417	Vulnerable	NIST National Vulnerability Database
Microsoft	Windows 10 Version 21H2	≥ 10.0.19044.0 and < 10.0.19044.7417	Vulnerable	CVE Program (cve.org) e CISA ADP
Microsoft	Windows 10 Version 22H2	≥ 10.0.19045.0 and < 10.0.19045.7417	Vulnerable	CVE Program (cve.org) e CISA ADP
Microsoft	Windows 11 23h2	< 10.0.22631.7219	Vulnerable	NIST National Vulnerability Database
Microsoft	Windows 11 24h2	< 10.0.26100.8655	Vulnerable	NIST National Vulnerability Database
Microsoft	Windows 11 25h2	< 10.0.26200.8655	Vulnerable	NIST National Vulnerability Database
Microsoft	Windows 11 26h1	< 10.0.28000.2269	Vulnerable	NIST National Vulnerability Database
Microsoft	Windows 11 version 23H2	≥ 10.0.22631.0 and < 10.0.22631.7219	Vulnerable	CVE Program (cve.org) e CISA ADP
Microsoft	Windows 11 Version 24H2	≥ 10.0.26100.0 and < 10.0.26100.8655	Vulnerable	CVE Program (cve.org) e CISA ADP
Microsoft	Windows 11 Version 25H2	≥ 10.0.26200.0 and < 10.0.26200.8655	Vulnerable	CVE Program (cve.org) e CISA ADP
Microsoft	Windows 11 version 26H1	≥ 10.0.28000.0 and < 10.0.28000.2269	Vulnerable	CVE Program (cve.org) e CISA ADP
Microsoft	Windows Server 2022	< 10.0.20348.5256	Vulnerable	NIST National Vulnerability Database
Microsoft	Windows Server 2022	≥ 10.0.20348.0 and < 10.0.20348.5256	Vulnerable	CVE Program (cve.org) e CISA ADP
Microsoft	Windows Server 2025	≥ 10.0.26100.0 and < 10.0.26100.32995	Vulnerable	CVE Program (cve.org) e CISA ADP
Microsoft	Windows Server 2025	< 10.0.26100.32995	Vulnerable	NIST National Vulnerability Database
Microsoft	Windows Server 2025 (Server Core installation)	≥ 10.0.26100.0 and < 10.0.26100.32995	Vulnerable	CVE Program (cve.org) e CISA ADP

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Attack vector

Local

Attack complexity

High

Privileges required

Low

User interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Every base score collected

Sources score independently and may disagree; each row says who scored it and under which version.

Score	Version	Severity	Expl.	Impact	Scored by
7.8	CVSS 3.1	High	1.8	5.9	secure@microsoft.com via NIST National Vulnerability Database
7.8	CVSS 3.1	High	—	—	microsoft via CVE Program (cve.org) e CISA ADP
7.0	CVSS 3.1	High	1.0	5.9	nvd@nist.gov via NIST National Vulnerability Database

CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H (score shown at the top: nvd@nist.gov)

Scoring entities (NIST, CNA, ADP) score independently; each score is shown with its origin. For prioritization we use 7.8 (secure@microsoft.com via NIST National Vulnerability Database) as a conservative provisional reference — not a definitive official score.

Weakness MITRE

Weakness class according to MITRE’s CWE catalog.

CWE-367 · TOCTOU Race Condition

Other CVEs with this weakness →

EPSS over time FIRST

Oct 13, 2026 → Oct 14, 2026 · 2 reading(s) · max 0.21%

Detection

Read off the CVSS vector and the weakness class. Starting points, not tested rules.

Local/physical vector: focus on endpoint telemetry (EDR) from affected hosts.

endpoint telemetry (EDR)

Timeline

What happened to this CVE, newest first.

2026
Affected products added · microsoft/windows 10 version 21h2, microsoft/windows 10 version 22h2, microsoft/windows 11 version 23h2, microsoft/windo
Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
SSVC assessment updated
Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
Record published
Oct 13, 2026
CVSS changed · 7.0
Oct 13, 2026 · NIST National Vulnerability Database
Source status changed · → Analyzed
Oct 13, 2026 · NIST National Vulnerability Database
Record created in this database
Oct 13, 2026 · NIST National Vulnerability Database
CVE published
Jun 9, 2026 · microsoft

Source activity

Repeated readings are counted rather than listed.

1× Official description updated · Oct 13, 2026 – Oct 13, 2026

References

1 on the record

msrc.microsoft.com/update-guide/vulnerability/CVE-2026-45487
Vendor Advisory, vendor-advisory, patch, NIST National Vulnerability Database

Elsewhere on this site

Microsoft
every CVE for this vendor

Logic error
same class

CWE-367
other pages naming this weakness

Related CVEs (same products)

Medium CVE-2026-97844 Role: DNS Server Information Disclosure Vulnerability 2d
Medium CVE-2026-97842 Role: DNS Server Information Disclosure Vulnerability 2d
Medium CVE-2026-97839 Role: DNS Server Information Disclosure Vulnerability 2d
Medium CVE-2026-97840 Role: DNS Server Information Disclosure Vulnerability 2d
Medium CVE-2026-97843 Role: DNS Server Information Disclosure Vulnerability 2d
Medium CVE-2026-97841 Role: DNS Server Information Disclosure Vulnerability 2d

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

No fixed version, patch or mitigation documented.
No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record

Text assembled only from the fields above — no additional claims.

What should defenders know first?

CVE-2026-45487 is "Windows Program Compatibility Assistant Service Elevation of Privilege Vulnerability", rated High. It affects Windows 10 21h2 (Microsoft); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 7.0 describes technical severity. EPSS 0.21% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.

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