What is CVE-2025-53771?
Improper authentication in Microsoft Office SharePoint allows an unauthorized attacker to perform spoofing over a network.
The record classifies CVE-2025-53771 under weakness class CWE-287. Its CVSS v3 base vector states that the flaw is reachable remotely over the network, needs no prior authentication, needs no user interaction. 3 affected-product entries are recorded, across 1 vendor, listed below. The identifier was first published 465 days ago.
Severity and exploitation probability
- CVSS v3.1 base score
- 6.5 — MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N - EPSS (FIRST)
- 99.8% probability of exploitation in the next 30 days, higher than 99.9% of all scored CVEs
- CISA KEV
- Not listed in the CISA Known Exploited Vulnerabilities catalog
- Threadlinqs priority
- 9.7/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
- Published
- 2025-07-20, last modified 2026-02-13
Is CVE-2025-53771 being exploited?
Weaponised exploit code for CVE-2025-53771 is publicly available. 1 public proof-of-concept repository is tracked for this identifier. A ProjectDiscovery Nuclei detection template exists (http/cves/2025/CVE-2025-53771.yaml). It currently carries a trending score of 45 in the Threadlinqs vulnerability feed.
- trickest/cve (trickest)
Affected products and versions
- Microsoft: Sharepoint Server, Sharepoint Server 2016, Sharepoint Server 2019
How to fix CVE-2025-53771
The record marks a vendor fix as available for CVE-2025-53771. Patch reference: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-53771. Vendor advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-53771. Apply the vendor fix referenced above to every affected product listed in this record, then confirm the running version against the vendor advisory.
Threat activity tracking CVE-2025-53771
6 tracked threats in the Threadlinqs corpus reference CVE-2025-53771, either in the campaign’s CVE list or as an indicator on the campaign record.
- Rapid7 Q3 2026 Threat Landscape: High-Severity Flaws Exploited in 3 Days as The Gentlemen and Qilin Ransomware Dominate — HIGH · 2026-10-21
- Warlock Ransomware Attackers Hit Water and Telecom Operators via SharePoint ToolShell Exploitation (Longlegs / Storm-2603) — CRITICAL · 2026-10-01
- CVE-2026-45659: SharePoint Deserialization RCE Added to CISA KEV Amid Storm-2603 Exploitation — HIGH · 2026-07-02
- CVE-2026-45659: Microsoft SharePoint Deserialization RCE Actively Exploited, Added to CISA KEV — HIGH · 2026-07-02
- Warlock (Water Manaul / Storm-2603) Ransomware Campaign with BYOVD, Web Shells, and Multi-Channel Tunneling via SharePoint Exploitation — CRITICAL · 2026-03-16
- APT31 Weaponizes Google Gemini AI for Automated Cyberattack Planning — CRITICAL · 2026-02-15
Sources
Enriched from CVE.org, FIRST EPSS, public proof-of-concept repositories, ProjectDiscovery Nuclei. Last verified by Threadlinqs on .