Microsoft Defender Link Following Vulnerability (CVE-2026-41091)
Severity: high · Patch status: unknown · Since 2026-05-20 · CVE-2026-41091
Microsoft Defender contains a link following vulnerability that allows an authorized attacker to elevate privileges locally. CISA added CVE-2026-41091 to its Known Exploited Vulnerabilities catalog on May 20, 2026, which means attackers are exploiting it in the wild.
What to do
- Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
- US federal agencies must remediate by Jun 3, 2026 (BOD 22-01); treat that as the outer limit.
Sources
All live incidents on Threat Watch
