# CVE-2026-85878 — Microsoft Azure HorizonDB

> As of 2026-10-08, CVE-2026-85878 is a CRITICAL-severity vulnerability in Microsoft Azure HorizonDB, CVSS v3.1 9.9, EPSS 0.7% (54.5th percentile). Threadlinqs Intelligence links 1 tracked threat campaign to CVE-2026-85878, most recently “Microsoft September 2026 Cloud Disclosure: 18 Elevation-of-Privilege, Information-Disclosure, and Spoofing Flaws Across Azure and Copilot AI Products, Plus a Windows Secure Kernel EoP (CVE-2026-85921)”.

**Last updated:** 2026-10-08

## What is CVE-2026-85878?

Improper authorization in Azure Database for PostgreSQL allows an authorized attacker to elevate privileges over a network.

The record classifies CVE-2026-85878 under weakness class [CWE-285](https://intel.threadlinqs.com/cwe/CWE-285). Its CVSS v3 base vector states that the flaw is reachable remotely over the network, needs low-privilege credentials, needs no user interaction, and has high impact on confidentiality, integrity, availability. 1 affected-product entry is recorded, across 1 vendor, listed below. The identifier was first published 37 days ago.

## Severity and exploitation probability

- **CVSS v3.1 base score:** 9.9 — CRITICAL (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H/E:U/RL:O/RC:C`)
- **EPSS (FIRST):** 0.7% probability of exploitation in the next 30 days, higher than 54.5% of all scored CVEs
- **CISA KEV:** Not listed in the CISA Known Exploited Vulnerabilities catalog
- **Threadlinqs priority:** 7.1/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
- **Published:** 2026-09-17, last modified 2026-10-08

## Is CVE-2026-85878 being exploited?

It currently carries a trending score of 43 in the Threadlinqs vulnerability feed.

## Affected products and versions

- [Microsoft](https://intel.threadlinqs.com/vendors/microsoft): Azure HorizonDB

## How to fix CVE-2026-85878

No vendor patch reference has been recorded for CVE-2026-85878 in the tracked sources. Follow the references below for a fix, and treat the products listed above as exposed until the vendor states otherwise.

## Threat activity tracking CVE-2026-85878

1 tracked threat in the Threadlinqs corpus references CVE-2026-85878, either in the campaign’s CVE list or as an indicator on the campaign record.

- [Microsoft September 2026 Cloud Disclosure: 18 Elevation-of-Privilege, Information-Disclosure, and Spoofing Flaws Across Azure and Copilot AI Products, Plus a Windows Secure Kernel EoP (CVE-2026-85921)](https://intel.threadlinqs.com/threat/TL-2026-2563) — CRITICAL · 2026-09-18

## Sources

Enriched from CVE.org, FIRST EPSS. Last verified by Threadlinqs on 2026-10-10.

**Vendor advisory and patch**

- [msrc.microsoft.com — vendor advisory](https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-85878)

Canonical: https://intel.threadlinqs.com/cve/CVE-2026-85878
Full detection coverage and IOCs for threats exploiting CVE-2026-85878 via the Threadlinqs MCP server (Purple tier): https://intel.threadlinqs.com/mcp