# CVE-2026-41091

Improper link resolution before file access ('link following') in Microsoft Defender allows an authorized attacker to elevate privileges locally.

- Page: https://www.vulneraibility.com/cve/CVE-2026-41091
- CVSS: 7.8
- Known exploited: yes, in CISA KEV since 2026-05-20; CISA due date 2026-06-03
- EPSS: 8.20%
- Unvetted proof-of-concept code on GitHub: 4 GitHub proofs of concept (first 2026-05-21)
- CISA SSVC: exploitation active, automatable no, technical impact total (assessed 2026-05-20)
- Weakness: CWE-59
- Published: 2026-05-20

## Affected versions

- Microsoft Microsoft Malware Protection Engine: affected >= 1.1.0.0 and < 1.1.26040.8

A version outside these ranges is not a statement that it is unaffected.

## References

- [patch] https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-41091
- [other] https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-41091

---
Summary, impact and action are written by the vulneraibility.com AI analysis pipeline from the CVE record, NVD, CISA and FIRST data; verify against the references.