Microsoft Defender Link Following Vulnerability

Microsoft Defender

Microsoft Defender contains a link following vulnerability that allows an authorized attacker to elevate privileges locally. Can be chained with CVE-2026-45498. Added to CISA KEV on 2026-05-20 (federal deadline 2026-06-03).

First seen: 20 May 2026
Last update: 20 May 2026, 12:00 UTC
Identifiers: CVE-2026-41091
CVE-2026-45498
Source: CISA KEV
On the menu as: Windows

Check this repository for exposure to one security incident from pwned.coffee. Report first, change nothing until I say so.

## Microsoft Defender Link Following Vulnerability
Severity: high, exploited in the wild. Patch status: patched.
Affected: Microsoft Defender
Ids: CVE-2026-41091, CVE-2026-45498

Microsoft Defender contains a link following vulnerability that allows an authorized attacker to elevate privileges locally. Can be chained with CVE-2026-45498. Added to CISA KEV on 2026-05-20 (federal deadline 2026-06-03).

## Steps
1. This touches infrastructure (windows). Look in terraform, ansible, cloud-init, Dockerfiles and docs for the product and version we run. If it isn't in the repo, say so and list what a human should check on the box.

## Report
A table: file, product or package, version in use, affected yes/no, exact fix. Then anything a human has to check outside the repo.

If you have the pwned.coffee MCP server (https://pwned.coffee/mcp), call lookup_cve("CVE-2026-41091") for the latest, and check_repo with this repo's lockfiles, Dockerfiles and workflows for a full receipt.
Sources: https://msrc.microsoft.com/update-guide/en-US/vulnerability/CVE-2026-41091 https://msrc.microsoft.com/update-guide/en-US/vulnerability/CVE-2026-45498 https://nvd.nist.gov/vuln/detail/CVE-2026-41091 https://nvd.nist.gov/vuln/detail/CVE-2026-45498
https://pwned.coffee/i/microsoft-defender-link-following-vulnerability

Sources

Totalone hot coffee