2026-004 Critical Vulnerability in SharePoint Exploited — CERT-EU-SA2026-004
CERT-EU · CERT-EU · CERT-EU-SA2026-004
ID
CERT-EU-SA2026-004
CERT-EU-SA2026-004
Date
Activity
Source
CERT-EU
CERT-EU
Vendor
CERT-EU
CERT-EU
Threat
critical
critical
Exploited
Yes
Yes
Summary
On 17 March 2026, Microsoft updated one of its January 2026 security advisories related to a remote code execution vulnerability in Microsoft SharePoint. Specifically, Microsoft raised the CVSS score and changed the FAQ section to indicate that the vulnerability could be exploited by an unauthenticated attacker. This vulnerability was added in the CISA's Known Exploited Vulnerabilities (KEV) catalogue on 18 March…
Product
Security advisory
What to do
General, cautious steps (verify details in the official source):
- Prioritize patching or mitigation immediately (treat as actively risky).
- Identify affected product versions in your inventory and verify whether you are impacted.
- Apply vendor patches/updates or recommended mitigations as soon as available.
- Check logs/telemetry for indicators of compromise and suspicious activity.
- Consider temporary hardening: restrict access, reduce attack surface, and monitor aggressively.
- Read the official advisory for exact affected versions and remediation steps.