What is CVE-2025-53770?
Deserialization of untrusted data in on-premises Microsoft SharePoint Server allows an unauthorized attacker to execute code over a network. Microsoft is aware that an exploit for CVE-2025-53770 exists in the wild. Microsoft is preparing and fully testing a comprehensive update to address this vulnerability. In the meantime, please make sure that the mitigation provided in this CVE documentation is in place so that you are protected from exploitation.
The record classifies CVE-2025-53770 under weakness class CWE-502. Its CVSS v3 base vector states that the flaw is reachable remotely over the network, needs no prior authentication, needs no user interaction, and has high impact on confidentiality, integrity, availability. 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
- 9.8 — CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - EPSS (FIRST)
- 99.9% probability of exploitation in the next 30 days, higher than 99.9% of all scored CVEs
- CISA KEV
- Listed since 2025-07-20, federal remediation deadline 2025-07-21 — used in known ransomware campaigns
- Threadlinqs priority
- 10/10 — CISA lists it as used in ransomware, which Threadlinqs scores at the maximum
- Published
- 2025-07-20, last modified 2026-08-04
Is CVE-2025-53770 being exploited?
CISA added CVE-2025-53770 to the Known Exploited Vulnerabilities catalog on 2025-07-20, which means the agency holds evidence of exploitation in the wild; US federal civilian agencies had to remediate it by 2025-07-21 under BOD 22-01. CISA flags the vulnerability as one used in known ransomware campaigns. Weaponised exploit code for CVE-2025-53770 is publicly available. 11 public proof-of-concept repositories are tracked for this identifier. A ProjectDiscovery Nuclei detection template exists (http/cves/2025/CVE-2025-53770.yaml). It currently carries a trending score of 55 in the Threadlinqs vulnerability feed.
- soltanali0/CVE-2025-53770-Exploit (github)
- MuhammadWaseem29/CVE-2025-53770 (github)
- hazcod/CVE-2025-53770 (github)
- kaizensecurity/CVE-2025-53770 (github)
- ZephrFish/CVE-2025-53770-Scanner (github)
- 3a7/CVE-2025-53770 (github)
- AdityaBhatt3010/CVE-2025-53770-SharePoint-Zero-Day-Variant-Exploited-for-Full-RCE (github)
- exfil0/CVE-2025-53770 (github)
Affected products and versions
- Microsoft: Sharepoint Server, Sharepoint Server 2016, Sharepoint Server 2019
How to fix CVE-2025-53770
Vendor advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-53770. Because CVE-2025-53770 is KEV-listed, US federal civilian agencies were required to apply the vendor fix, or stop using the product, by 2025-07-21. 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-2025-53770
7 tracked threats in the Threadlinqs corpus reference CVE-2025-53770, 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-2026-56164: Microsoft SharePoint Server Missing-Authentication Vulnerability Actively Exploited, Added to CISA KEV — CRITICAL · 2026-07-15
- 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, NVD, FIRST EPSS, CISA KEV, public proof-of-concept repositories, ProjectDiscovery Nuclei. Last verified by Threadlinqs on . This product uses the NVD API but is not endorsed or certified by the NVD.
Vendor advisory and patch
Other references
Showing 6 of 10 recorded references.