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

Time-of-check time-of-use (TOCTOU) race condition in Program Compatibility Assistant Service allows an authorized attacker to elevate privileges locally.

Published: 2026-06-09 Last update: 2026-06-17 Assigner: [email protected] Source: [email protected]
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2026-45487 is rated Low Risk (34/100): CVSS High severity, with low exploitation likelihood (EPSS 0.18%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2026-45487

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-23 0.15% 0.18% +0.04%
2 2026-06-15 0.05% 0.15% +0.10%
3 2026-06-12 — 0.05% —

Full EPSS history (4 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-45487

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.8 3.1 HIGH
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 1.8 5.9 [email protected]
7.0 3.1 HIGH
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 1.0 5.9 [email protected]

Weakness enumeration for CVE-2026-45487

GitHub Security Advisory for CVE-2026-45487

GHSA-fj7f-jv57-m7jh · Severity: high — Time-of-check time-of-use (TOCTOU) race condition in Program Compatibility Assistant Service...

Affected software / configurations for CVE-2026-45487

Vendor Product Version Raw CPE
microsoft windows_10_21h2 < 10.0.19044.7417 cpe:2.3:o:microsoft:windows_10_21h2:*:*:*:*:*:*:arm64:*
microsoft windows_10_21h2 < 10.0.19044.7417 cpe:2.3:o:microsoft:windows_10_21h2:*:*:*:*:*:*:x64:*
microsoft windows_10_21h2 < 10.0.19044.7417 cpe:2.3:o:microsoft:windows_10_21h2:*:*:*:*:*:*:x86:*
microsoft windows_10_22h2 < 10.0.19045.7417 cpe:2.3:o:microsoft:windows_10_22h2:*:*:*:*:*:*:arm64:*
microsoft windows_10_22h2 < 10.0.19045.7417 cpe:2.3:o:microsoft:windows_10_22h2:*:*:*:*:*:*:x64:*
microsoft windows_10_22h2 < 10.0.19045.7417 cpe:2.3:o:microsoft:windows_10_22h2:*:*:*:*:*:*:x86:*
microsoft windows_11_23h2 < 10.0.22631.7219 cpe:2.3:o:microsoft:windows_11_23h2:*:*:*:*:*:*:arm64:*
microsoft windows_11_23h2 < 10.0.22631.7219 cpe:2.3:o:microsoft:windows_11_23h2:*:*:*:*:*:*:x64:*
microsoft windows_11_24h2 < 10.0.26100.8655 cpe:2.3:o:microsoft:windows_11_24h2:*:*:*:*:*:*:arm64:*
microsoft windows_11_24h2 < 10.0.26100.8655 cpe:2.3:o:microsoft:windows_11_24h2:*:*:*:*:*:*:x64:*
microsoft windows_11_25h2 < 10.0.26200.8655 cpe:2.3:o:microsoft:windows_11_25h2:*:*:*:*:*:*:arm64:*
microsoft windows_11_25h2 < 10.0.26200.8655 cpe:2.3:o:microsoft:windows_11_25h2:*:*:*:*:*:*:x64:*
microsoft windows_11_26h1 < 10.0.28000.2269 cpe:2.3:o:microsoft:windows_11_26h1:*:*:*:*:*:*:arm64:*
microsoft windows_11_26h1 < 10.0.28000.2269 cpe:2.3:o:microsoft:windows_11_26h1:*:*:*:*:*:*:x64:*
microsoft windows_server_2022 < 10.0.20348.5256 cpe:2.3:o:microsoft:windows_server_2022:*:*:*:*:*:*:*:*
microsoft windows_server_2025 < 10.0.26100.32995 cpe:2.3:o:microsoft:windows_server_2025:*:*:*:*:*:*:x64:*

References for CVE-2026-45487

cvelogic Threat Intelligence