CVE-2025-53770 | Microsoft SharePoint Server Remote Code Execution Vulnerability

Exp

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.

Published: 2025-07-20 Last update: 2025-10-27 Assigner: [email protected] Source: [email protected]
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2025-53770 is rated Critical Active Threat (98.7/100): CVSS Critical severity, with high exploitation likelihood (EPSS 88.18%, 100th percentile). CISA KEV confirms active exploitation (added 2025-07-20) affecting Microsoft / SharePoint. a weakness (CWE-502) Unauthenticated remote administrative access may be possible. The CISA remediation deadline has passed—treat as an emergency patch priority.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

CISA KEV Record for CVE-2025-53770

Name: Microsoft SharePoint Deserialization of Untrusted Data Vulnerability · CISA KEV detail

Exploit added: 2025-07-20

Action due: 2025-07-21

Required action: Disconnect public-facing versions of SharePoint Server that have reached their end-of-life (EOL) or end-of-service (EOS) to include SharePoint Server 2013 and earlier versions. For supported versions, please follow the mitigations according to CISA (URL listed below in Notes) and vendor instructions (URL listed below in Notes). Adhere to the applicable BOD 22-01 guidance for cloud services or discontinue use of the product if mitigations are not available.

Public exploit references (Exploit-DB) for CVE-2025-53770

EDB-ID Source Kind Published Link
52405 exploit_db edb 2025-08-11 Exploit-DB ↗
— nvd_ref exploit_tag Exploit-DB ↗
— nvd_ref exploit_tag Exploit-DB ↗
— nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2025-53770

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-06 88.54% 88.18% -0.35%
2 2026-05-28 90.21% 88.54% -1.67%
3 2026-05-24 — 90.21% —

Full EPSS history (83 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2025-53770

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
9.8 3.1 CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 5.9 [email protected]

Weakness enumeration for CVE-2025-53770

Affected software / configurations for CVE-2025-53770

Vendor Product Version Raw CPE
microsoft sharepoint_server < 16.0.18526.20508 cpe:2.3:a:microsoft:sharepoint_server:*:*:*:*:subscription:*:*:*
microsoft sharepoint_server 2016 cpe:2.3:a:microsoft:sharepoint_server:2016:*:*:*:enterprise:*:*:*
microsoft sharepoint_server 2019 cpe:2.3:a:microsoft:sharepoint_server:2019:*:*:*:*:*:*:*

References for CVE-2025-53770

URL Tags
https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-53770 Vendor Advisory
https://arstechnica.com/security/2025/07/sharepoint-vulnerability-with-9-8-severity-rating-is-under-exploit-across-the-globe/ Exploit Press/Media Coverage
https://github.com/kaizensecurity/CVE-2025-53770 Exploit
https://msrc.microsoft.com/blog/2025/07/customer-guidance-for-sharepoint-vulnerability-cve-2025-53770/ Mitigation Vendor Advisory
https://news.ycombinator.com/item?id=44629710 Issue Tracking
https://research.eye.security/sharepoint-under-siege/ Exploit Mitigation Third Party Advisory
https://therecord.media/microsoft-sharepoint-zero-day-vulnerability-exploited-globally Press/Media Coverage
https://www.bleepingcomputer.com/news/microsoft/microsoft-sharepoint-zero-day-exploited-in-rce-attacks-no-patch-available/ Press/Media Coverage
https://www.cisa.gov/news-events/alerts/2025/07/20/microsoft-releases-guidance-exploitation-sharepoint-vulnerability-cve-2025-53770 Mailing List Third Party Advisory US Government Resource
https://www.darkreading.com/remote-workforce/microsoft-rushes-emergency-fix-exploited-sharepoint-toolshell-flaw Press/Media Coverage
https://www.forbes.com/sites/daveywinder/2025/07/20/microsoft-confirms-ongoing-mass-sharepoint-attack---no-patch-available/ Press/Media Coverage
https://x.com/Shadowserver/status/1946900837306868163 Third Party Advisory
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-53770 US Government Resource
cvelogic Threat Intelligence