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PatchSiren cyber security CVE debrief

CVE-2025-24991 Microsoft CVE debrief

CVE-2025-24991 is a Microsoft Windows NTFS out-of-bounds read vulnerability that CISA added to its Known Exploited Vulnerabilities catalog on 2025-03-11. Because it is tracked as known exploited, defenders should treat it as an urgent remediation item and follow Microsoft’s update guidance and CISA’s required actions without delay.

Vendor
Microsoft
Product
Windows
CVSS
Unknown
CISA KEV
Listed
Original CVE published
2025-03-11
Original CVE updated
2025-03-11
Advisory published
2025-03-11
Advisory updated
2025-03-11

Who should care

Windows administrators, endpoint security teams, incident responders, and any organization operating Microsoft Windows systems that use NTFS, especially where systems are internet-facing, business-critical, or difficult to patch quickly.

Technical summary

The supplied corpus identifies the issue as an out-of-bounds read in Windows NTFS. The authoritative CISA KEV entry marks it as a known exploited vulnerability, with a remediation due date of 2025-04-01. The available sources do not provide additional exploit-chain details, so defensive handling should center on vendor guidance, patching, and exposure reduction.

Defensive priority

Urgent

Recommended defensive actions

  • Review Microsoft’s update guide for CVE-2025-24991 and apply the vendor’s mitigation or update guidance as soon as possible.
  • Inventory Windows systems that use NTFS and prioritize remediation for endpoints and servers with the highest exposure or business impact.
  • Use CISA’s KEV catalog and due date of 2025-04-01 to drive tracking and escalation for completion.
  • If mitigations are not available for a specific deployment, follow CISA’s required action guidance to discontinue use or reduce exposure where feasible.
  • Validate remediation across managed fleets and document exception handling for any systems that cannot be updated immediately.

Evidence notes

The source corpus shows CVE-2025-24991 in the CISA Known Exploited Vulnerabilities JSON feed as "Microsoft Windows NTFS Out-Of-Bounds Read Vulnerability," with dateAdded 2025-03-11, dueDate 2025-04-01, and knownRansomwareCampaignUse marked Unknown. CISA’s record also references Microsoft’s update guide and NVD as supporting resources. The corpus does not include detailed vendor advisory text, exploit mechanics, or confirmed ransomware attribution beyond the KEV designation.

Official resources

Publicly disclosed in the supplied corpus on 2025-03-11 and added to CISA KEV the same day. The corpus does not confirm exploit technique details or ransomware linkage beyond CISA’s "known exploited" designation and Unknown ransomware-camp​