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.
do firstDisconnect 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.
Can a WAF block it? Partly. Cloudflare publishes WAF a rule written for this CVE. Such rules block the known exploit requests and buy time, but attackers can change the request to get past them, so they do not replace the patch.
Cloudflare · 1 rule (Block) · since 21 Jul 2025
- Microsoft SharePoint - Deserialization - CVE:CVE-2025-53770 · Cloudflare Managed Ruleset
Also consider: patch · enable the vendor rule in block mode · allow-list classes
Based on WAF vendor rules published for this CVE. We check Cloudflare, AWS, Google Cloud Armor and Azure; for Akamai, Imperva, Fastly, F5, ask your vendor.
Is CVE-2025-53770 being exploited?
Yes. CVE-2025-53770 appears in CISA's Known Exploited Vulnerabilities catalog, which means exploitation in the wild has been confirmed and reported. Treat it as active rather than theoretical, and patch it ahead of higher-scoring vulnerabilities that carry no exploitation evidence.
How severe is CVE-2025-53770?
CVE-2025-53770 is rated Critical with a CVSS score of 9.8. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2025-53770?
Yes. A fix has been recorded for CVE-2025-53770. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2025-53770 affect?
CVE-2025-53770 affects microsoft:sharepoint_server. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
- affected>= 16.0.0 and < 16.0.5513.1001
- affected>= 16.0.0 and < 16.0.10417.20037
- affected>= 16.0.0 and < 16.0.18526.20508
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.
public exploits
Public exploit code: 1 on Exploit-DB · 1 Metasploit module · 45 GitHub proofs of concept · 1 Nuclei template
- Microsoft SharePoint Server 2019 (16.0.10383.20020) - Remote Code Execution (RCE) · remote · 11 Aug 2025
- exploit/windows/http/sharepoint_toolpane_rce · exploit · excellent
- Microsoft SharePoint Server - Remote Code Execution (ToolShell) · detection template · critical
- soltanali0/CVE-2025-53770-Exploit · 316 ★
- MuhammadWaseem29/CVE-2025-53770 · 57 ★
- hazcod/CVE-2025-53770 · 45 ★
- kaizensecurity/CVE-2025-53770 · 44 ★
Listed so you can judge urgency, not as a recommendation to run anything. GitHub “proofs of concept” are unvetted: some are fake or carry malware. Exploit-DB marks the entries its staff verified.
cisa ssvc
- exploitation
- active
- automatable
- yes
- technical impact
- total
Assessed by CISA 20 Jul 2025 (SSVC 2.0.3).
timeline
- 20 Jul 2025Added to CISA KEV (exploited in the wild)
- 20 Jul 2025CISA SSVC assessment: exploitation active · same day later
- 20 Jul 2025Published · same day later
- 21 Jul 2025First public exploit or proof of concept · 1 day later
- 21 Jul 2025CISA remediation due date (US federal agencies) · same day later
- 4 Aug 2026CVE record last updated · 379 days (about 1 year) later
- 2 Nov 2026Analysed by vulneraibility.com · 91 days (about 3 months) later
- Patchmsrc.microsoft.com /update-guide/vulnerability/CVE-2025-53770
- Linkcisa.gov /known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-53770
- Linkmsrc.microsoft.com /blog/2025/07/customer-guidance-for-sharepoint-vulnerability-cve-2025-53770/
- Linkcisa.gov /news-events/alerts/2025/07/20/microsoft-releases-guidance-exploitation-sharepoi
- Linkresearch.eye.security /sharepoint-under-siege/
- Linkbleepingcomputer.com /news/microsoft/microsoft-sharepoint-zero-day-exploited-in-rce-attacks-no-patch-
- Linkforbes.com /sites/daveywinder/2025/07/20/microsoft-confirms-ongoing-mass-sharepoint-attack-
- Linkx.com /Shadowserver/status/1946900837306868163
Show 5 more
- Linkgithub.com /kaizensecurity/CVE-2025-53770
- Linktherecord.media /microsoft-sharepoint-zero-day-vulnerability-exploited-globally
- Linknews.ycombinator.com /item?id=44629710
- Linkarstechnica.com /security/2025/07/sharepoint-vulnerability-with-9-8-severity-rating-is-under-exp
- Linkdarkreading.com /remote-workforce/microsoft-rushes-emergency-fix-exploited-sharepoint-toolshell-
sources
- CVE List (CVE.org): description, affected versions, references; CVE Terms of Use
- NVD: CVSS and CPE data
- CISA KEV catalog: exploitation, date added, due date
- CISA Vulnrichment (ADP): SSVC decision points
- FIRST EPSS: exploit probability and percentile
- Exploit-DB: published exploits
- Metasploit Framework: exploit and scanner modules
- Nuclei templates: detection templates
- PoC-in-GitHub: GitHub repositories that claim a proof of concept
- Summary, impact and triage tags: written by our AI analysis pipeline from the sources above. Check them against the sources.