CISA: Microsoft SharePoint RCE flaw now actively exploited
CISA warns of active exploitation of a critical Microsoft SharePoint RCE vulnerability.
CISA has issued a warning that a critical remote code execution vulnerability in Microsoft SharePoint, tracked as CVE-2026-45659, is now being actively exploited by attackers. The flaw allows authenticated attackers with minimal privileges to execute arbitrary code on unpatched servers with low complexity attacks. CISA has added it to its Known Exploited Vulnerabilities Catalog and mandated federal agencies to patch it by Saturday.
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The lesson from this incident
Full lessonA critical remote code execution vulnerability in Microsoft SharePoint (CVE-2026-45659) is being actively exploited in the wild, allowing authenticated attackers with low privileges to execute arbitrary code on unpatched servers. The low complexity of the attack significantly lowers the barrier for threat actors, meaning even moderately skilled attackers can weaponize this flaw quickly. CISA's addition to the Known Exploited Vulnerabilities (KEV) Catalog underscores the urgency, as federal agencies have been given a hard deadline to patch. This incident highlights how delayed patching of internet-facing collaboration platforms can expose organizations to full system compromise. The broader lesson is that critical patches for widely-used enterprise software must be treated as emergency responses, not routine maintenance cycles.
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Indicators of Compromise
Extracted by AI from the linked source. Not reviewed by an editor. How this works
- cve — CVE-2026-45659