CVE-2026-105009
HIGH 7.5Incorrect default permissions in Windows Server Update Service allows an authorized attacker to elevate privileges locally.
Severe if exploited (CVSS 7.5), but no known exploitation and low modeled probability. Patch on a normal cadence.
Exploitation likelihood
0.3%chance of exploitation in 30 days · 20th percentile
Impact if exploited
7.5CVSS 3.1 · HIGH
- ConfidentialityHigh
- IntegrityHigh
- AvailabilityHigh
What an attacker needs
- ⚠Access: Requires local access to the host
- ⚠Privileges: Requires a low-privilege account
- ⚠User interaction: A user must take an action (click / open a file)
- ⚠Complexity: Needs a race window or specific setup
✓ lowers the bar for an attacker · ⚠ raises it
Proof of concept & exploit code
- github-search Search GitHub for public PoC repos
Test against your own equipment
curl -s https://vulnpedia.com/cve/CVE-2026-105009/poc.jsonMachine-readable PoC index for this CVE (for automation).Listed for defensive triage, patch verification, and authorized testing on systems you own. Machine-readable: /cve/CVE-2026-105009/poc.json
Affected
Vendors Microsoft
Products Windows Server 2012 Windows Server 2012 (Server Core Installation) Windows Server 2012 R2 Windows Server 2012 R2 (Server Core Installation) Windows Server 2016 Windows Server 2016 (Server Core Installation) Windows Server 2019 Windows Server 2019 (Server Core Installation) Windows Server 2022 Windows Server 2025 Windows Server 2025 (Server Core Installation)
Weakness (CWE)
- CWE-276: : Incorrect Default Permissions
CVSS vector
CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:C/C:H/I:H/A:H/E:U/RL:O/RC:C
All CVSS metrics
- HIGH 7.5 v3.1 · CNA Primary
CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:C/C:H/I:H/A:H/E:U/RL:O/RC:C - HIGH 7.5 v3.1 · NVD Secondary
CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:C/C:H/I:H/A:H