# CVE-2025-53770: Microsoft SharePoint Deserialization of Untrusted Data

> Unauthorized attackers can execute code remotely via deserialization in Microsoft SharePoint Server, requiring immediate mitigation and patching.

- **Severity:** Critical 9.8 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:F/RL:W/RC:C`)
- **Exploited in the wild:** Yes, since 20 Jul 2025 (CISA KEV), used in ransomware
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 20 Jul 2025
- **Updated:** 4 Aug 2026
- **Also known as:** GHSA-xcrc-8vqv-vc8r

## What is CVE-2025-53770?

CVE-2025-53770 is a critical unsafe deserialization vulnerability in Microsoft Sharepoint Server, published on 20 Jul 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official 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.

Weakness: CWE-502 (Deserialization of Untrusted Data)

## Which versions are affected by CVE-2025-53770?

It affects 1 product.


Products: Microsoft Sharepoint Server.

## How do I fix CVE-2025-53770?

No fix has been published for CVE-2025-53770 yet. Limit exposure of the affected software until one is available. US federal agencies must fix it by 21 Jul 2025.

## Is CVE-2025-53770 being exploited?

Yes. Attackers have exploited CVE-2025-53770 in the wild since at least 20 Jul 2025, including in ransomware campaigns.

Public exploit code:

- SharePoint WebPart Injection Exploit Tool (github_poc): https://github.com/soltanali0/CVE-2025-53770-Exploit
- Unauthenticated Remote Code Execution via unsafe deserialization in Microsoft SharePoint Server (CVE-2025-53770) (github_poc): https://github.com/MuhammadWaseem29/CVE-2025-53770
- Scanner for the SharePoint CVE-2025-53770 RCE zero day vulnerability. (github_poc): https://github.com/hazcod/CVE-2025-53770
- POC (github_poc): https://github.com/kaizensecurity/CVE-2025-53770
- ToolShell scanner - CVE-2025-53770 and detection information (github_poc): https://github.com/ZephrFish/CVE-2025-53770-Scanner
- CVE-2025-53770 Mass Scanner (github_poc): https://github.com/3a7/CVE-2025-53770

## Other vulnerabilities in Microsoft Sharepoint Server

- [CVE-2026-50522](https://insights.sbomify.com/CVE-2026-50522/): Microsoft SharePoint Deserialization of Untrusted Data Vulnerability (critical 9.8, exploited in the wild)
- [CVE-2026-58644](https://insights.sbomify.com/CVE-2026-58644/): Microsoft SharePoint Deserialization of Untrusted Data (critical 9.8, exploited in the wild)
- [CVE-2026-20963](https://insights.sbomify.com/CVE-2026-20963/): Microsoft SharePoint Deserialization of Untrusted Data (critical 9.8, exploited in the wild)
- [CVE-2023-29357](https://insights.sbomify.com/CVE-2023-29357/): Microsoft SharePoint Server Privilege Escalation (critical 9.8, exploited in the wild)
- [CVE-2026-55040](https://insights.sbomify.com/CVE-2026-55040/): Microsoft SharePoint Weak Authentication (critical 9.1, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-53770 and fix it if it is affected.

What it is: CVE-2025-53770 is a critical unsafe deserialization vulnerability in Microsoft Sharepoint Server, published on 20 Jul 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: Yes. Attackers have exploited CVE-2025-53770 in the wild since at least 20 Jul 2025, including in ransomware campaigns.

Affected product: Microsoft Sharepoint Server. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2025-53770/ (Markdown: https://insights.sbomify.com/CVE-2025-53770/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-53770
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-53770
- OSV: https://osv.dev/vulnerability/CVE-2025-53770

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-53770/
Summaries are generated and may contain mistakes; the official description above is the record.