CVE-2025-53770

critical

Description

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.

From the Tenable Blog

CVE-2025-53770: Frequently Asked Questions About Zero-Day SharePoint Vulnerability Exploitation

Published: 2025-07-20

Successful exploitation of CVE-2025-53770 could expose MachineKey configuration details from a vulnerable SharePoint Server, ultimately enabling unauthenticated remote code execution.

References

https://securelist.com/vulnerabilities-and-exploits-in-q2-2026/121091/

https://blog.talosintelligence.com/year-in-review-vulnerabilities-old-and-new-and-something-react2/

https://storage.ghost.io/c/af/a0/afa04ee3-414f-4481-8d23-7e7c146f192e/content/files/2026/03/2025YiR-report.pdf

https://www.helpnetsecurity.com/2026/03/24/enterprise-vulnerability-exploitation-cybersecurity-threats/

https://cyberscoop.com/social-engineering-surge-intrusion-vector-mandiant-m-trends/

https://www.theregister.com/2026/03/19/unknown_attackers_exploit_yet_another/

https://cloud.google.com/blog/topics/threat-intelligence/ransomware-ttps-shifting-threat-landscape/

https://cyberscoop.com/vulncheck-exploited-vulnerabilities-report-2025/

https://www.greynoise.io/blog/unmasking-cisas-hidden-kev-ransomware-updates

https://thehackernews.com/2025/12/new-forumtroll-phishing-attacks-target.html

https://securelist.com/vulnerabilities-and-exploits-in-q3-2025/118197/

https://www.infosecurity-magazine.com/news/toolshell-gains-traction/

https://securityaffairs.com/183800/security/china-linked-hackers-exploit-patched-toolshell-flaw-to-breach-middle-east-telecom.html

https://www.cybereason.com/blog/ttp-briefing-q3-2025

https://blog.talosintelligence.com/ir-trends-q3-2025/

https://www.security.com/threat-intelligence/warlock-ransomware-origins

https://www.bleepingcomputer.com/news/security/sharepoint-toolshell-attacks-targeted-orgs-across-four-continents/

https://therecord.media/sharepoint-toolshell-bug-breaches-governments-africa-south-america

https://thehackernews.com/2025/10/chinese-threat-actors-exploit-toolshell.html

https://news.sophos.com/en-us/2025/09/17/gold-salems-warlock-operation-joins-busy-ransomware-landscape/

https://www.darkreading.com/vulnerabilities-threats/sitecore-zero-day-viewstate-threats

https://www.trendmicro.com/en_us/research/25/h/warlock-ransomware.html

https://www.darkreading.com/vulnerabilities-threats/warlock-ransomware-targets-vulnerable-sharepoint-servers

https://securityaffairs.com/181247/data-breach/colt-technology-faces-multi-day-outage-after-warlock-ransomware-attack.html

https://www.bleepingcomputer.com/news/security/colt-telecom-attack-claimed-by-warlock-ransomware-data-up-for-sale/

https://securityaffairs.com/181155/hacking/hackers-exploit-microsoft-flaw-to-breach-canada-s-house-of-commons.html

https://www.bleepingcomputer.com/news/security/canadas-house-of-commons-investigating-data-breach-after-cyberattack/

https://cyberscoop.com/microsoft-patch-tuesday-august-2025/

https://www.trustwave.com/en-us/resources/blogs/spiderlabs-blog/echoes-in-the-shell-legacy-tooling-behind-ongoing-sharepoint-toolshell-exploitation/

https://www.theregister.com/2025/08/07/cisa_releases_malware_analysis/

https://www.bleepingcomputer.com/news/security/ransomware-gangs-join-attacks-targeting-microsoft-sharepoint-servers/

https://unit42.paloaltonetworks.com/microsoft-sharepoint-cve-2025-49704-cve-2025-49706-cve-2025-53770/

https://www.infosecurity-magazine.com/news/396-sharepoint-systems-compromised/

https://www.welivesecurity.com/en/eset-research/toolshell-an-all-you-can-eat-buffet-for-threat-actors/

https://www.securityweek.com/toolshell-attacks-hit-400-sharepoint-servers-us-government-victims-named/

https://www.darkreading.com/endpoint-security/ransomware-actors-toolshell-sharepoint-bugs

https://www.bleepingcomputer.com/news/security/microsoft-sharepoint-servers-also-targeted-in-ransomware-attacks/

https://cyberscoop.com/microsoft-sharepoint-attacks-400-victims-us-agencies/

https://www.bleepingcomputer.com/news/security/us-nuclear-weapons-agency-reportedly-hacked-in-sharepoint-attacks/

https://www.bleepingcomputer.com/news/security/us-nuclear-weapons-agency-hacked-in-microsoft-sharepoint-attacks/

https://www.helpnetsecurity.com/2025/08/13/microsoft-fixes-badsuccessor-kerberos-vulnerability-cve-2025-53779/

https://securelist.com/toolshell-explained/117045/

https://www.theregister.com/2025/07/24/microsoft_sharepoint_ransomware/

https://www.tenable.com/blog/cve-2026-32201-cve-2026-45659-cve-2026-56164-faq-sharepoint-server-exploitation

https://github.com/CedricG-dev/nvd-mcp

https://github.com/mfarshad-abdullah-khan/cve-2025-53770-research

https://github.com/Chackey999/cybersecurity-portfolio

https://github.com/hanmin0512/CVE_Lab

https://github.com/doerrdan/it-sec-toolshell

https://github.com/Zedocun/SharePoint-ToolShell-CVE-2025-53770-Incident-Analysis

https://github.com/rbctee/CVE-2025-53770

https://github.com/CipherX9FSecurity/CVE-Exploitation-Analysis

https://github.com/anwakub/CVE-2025-53770

https://github.com/32BitZ-Studio/Total-POC-CVE

https://github.com/Cameloo1/sharepoint-toolshell-micro-postmortem

https://github.com/ozdalva/cve-crawler

https://github.com/Michaael01/LetsDefend--SOC-342-CVE-2025-53770-SharePoint-Exploit-ToolShell

https://github.com/saladin0x1/CVE-2025-53770

https://github.com/khizar-anjum/risky-business-mcp

https://github.com/ghostn4444/CVE-2025-53770

https://github.com/CyprianAtsyor/ToolShell-CVE-2025-53770-SharePoint-Exploit-Lab-LetsDefend

https://github.com/vjackl001/cve-search-tool

https://github.com/Agampreet-Singh/CVE-2025-53770

https://github.com/rlawlwhs/CVEDictionary

https://github.com/harryhaxor/CVE-2025-53770-SharePoint-Deserialization-RCE-PoC

https://github.com/Immersive-Labs-Sec/SharePoint-CVE-2025-53770-POC

https://github.com/0x-crypt/CVE-2025-53770-Scanner

https://github.com/daryllundy/CVE-2025-53770

https://github.com/r3xbugbounty/CVE-2025-53770

https://github.com/3a7/CVE-2025-53770

https://github.com/bossnick98/-SOC342---CVE-2025-53770-SharePoint-ToolShell-Auth-Bypass-and-RCE

https://github.com/unk9vvn/sharepoint-toolpane

https://github.com/Udyz/CVE-2025-53770-Exploit

https://github.com/Rabbitbong/OurSharePoint-CVE-2025-53770

https://github.com/bharath-cyber-root/sharepoint-toolshell-cve-2025-53770

https://github.com/nisargsuthar/suricata-rule-CVE-2025-53770

https://github.com/zach115th/ToolShellFinder

https://github.com/yembors64632/cve_monitor_Public

https://github.com/bijikutu/CVE-2025-53770-Exploit

Details

Source: Mitre, NVD

Published: 2025-07-20

Updated: 2026-08-04

Named Vulnerability: ToolShellKnown Exploited Vulnerability (KEV)

Risk Information

CVSS v2

Base Score: 10

Vector: CVSS2#AV:N/AC:L/Au:N/C:C/I:C/A:C

Severity: Critical

CVSS v3

Base Score: 9.8

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Severity: Critical

EPSS

EPSS: 0.99998

Vulnerability Watch

Tenable Research has classified this CVE under the following Vulnerability Watch classification, which includes active and historical (inactive) classifications. You can learn more about these classifications on our blog.

Vulnerability of Concern

Detections

Analytics