Microsoft — Windows Client-Side Caching (CSC) Service Elevation of Privilege Vulnerability
Patch Tuesday
An EPSS probability of 0.003, and Microsoft Exploitability Index: Exploitation More Likely.
Scheduled Maintenance
The priority band answers “how soon”, not “how bad” — see Methodology for what it weighs and where it abstains.
| Measure | Value | Source | What it means |
|---|---|---|---|
| CVSS base score | 7.0 | — | How severe the flaw is in itself. It does not say how likely an attack is. |
| FIRST EPSS | 0.003 (19.8th pctl) | FIRST | FIRST's estimate of the chance this is exploited in the next 30 days, and how that ranks against all CVEs. |
| Actively exploited | Not confirmed | Patch Tuesday | Whether a source of record has confirmed attacks using it in the wild. |
| Public exploit module | None known | Metasploit | Module existing is not the same as active exploitation. |
| EUVD cross-reference | Listed | ENISA EUVD | ENISA's own vulnerability database entry for this CVE, where one exists. |
Impacted software or hardware: Not identified by the connected sources
Remediation: Apply the vendor patch or guidance: https://github.com/advisories/GHSA-478f-j54x-44rp | https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-83580
Remediation basis: External remediation intelligence
ENISA EUVD also lists this CVE at CVSS 7.0 (v3.1), assigned by microsoft. Source: euvd.enisa.europa.eu.
0.29% as of 2026-10-16 (19.8th percentile). FIRST EPSS, recorded daily since this page started tracking it.
This page is an opinion about urgency. Where it and a source of record disagree, the source of record is the record.
Where this sits
CVE-2026-83580 is one of the entries ranked on the priority feed and in this month's Microsoft release.
