# CVE-2025-53786: Microsoft Exchange Server Hybrid Deployment Elevation of Privilege Vulnerability

> Attackers can escalate privileges in Microsoft Exchange Server hybrid deployments by exploiting specific configuration steps outlined in April 2025 security guidance.

- **Severity:** High 8.0 (`CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:H/E:U/RL:O/RC:C`)
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 6 Aug 2025
- **Updated:** 26 Feb 2026
- **Also known as:** GHSA-v92c-556h-xm93

## What is CVE-2025-53786?

CVE-2025-53786 is a high-severity vulnerability in Microsoft Exchange Server, published on 6 Aug 2025. An attacker needs administrator access to exploit it, with no action from the victim.

### Official description

On April 18th 2025, Microsoft announced Exchange Server Security Changes for Hybrid Deployments and accompanying non-security Hot Fix. Microsoft made these changes in the general interest of improving the security of hybrid Exchange deployments. Following further investigation, Microsoft identified specific security implications tied to the guidance and configuration steps outlined in the April announcement. Microsoft is issuing CVE-2025-53786 to document a vulnerability that is addressed by taking the steps documented with the April 18th announcement. Microsoft strongly recommends reading the information, installing the April 2025 (or later) Hot Fix and implementing the changes in your Exchange Server and hybrid environment.

Weakness: CWE-287 (Improper Authentication)

## Which versions are affected by CVE-2025-53786?

It affects 2 products.


Products: Microsoft Exchange Server, Microsoft Exchange Server Subscription Edition.

## How do I fix CVE-2025-53786?

No fix has been published for CVE-2025-53786 yet. Limit exposure of the affected software until one is available.

## Is CVE-2025-53786 being exploited?

There is no known exploitation of CVE-2025-53786 in the wild and no public exploit code.

Public exploit code:

- https://github.com/vincentdthe/CVE-2025-53786 (github_poc): https://github.com/vincentdthe/CVE-2025-53786

## Other vulnerabilities in Microsoft Exchange Server

- [CVE-2024-21410](https://insights.sbomify.com/CVE-2024-21410/): Microsoft Exchange Server Privilege Escalation (critical 9.8, exploited in the wild)
- [CVE-2021-34473](https://insights.sbomify.com/CVE-2021-34473/): Microsoft Exchange Server Remote Code Execution (critical 9.1, exploited in the wild)
- [CVE-2021-26855](https://insights.sbomify.com/CVE-2021-26855/): Microsoft Exchange Server Remote Code Execution (critical 9.1, exploited in the wild)
- [CVE-2021-34523](https://insights.sbomify.com/CVE-2021-34523/): Microsoft Exchange Server Privilege Escalation (critical 9.0, exploited in the wild)
- [CVE-2023-21529](https://insights.sbomify.com/CVE-2023-21529/): Microsoft Exchange Server Deserialization of Untrusted Data (high 8.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-53786 and fix it if it is affected.

What it is: CVE-2025-53786 is a high-severity vulnerability in Microsoft Exchange Server, published on 6 Aug 2025. An attacker needs administrator access to exploit it, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2025-53786 in the wild and no public exploit code.

Affected product: Microsoft Exchange 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-2025-53786/ (Markdown: https://insights.sbomify.com/CVE-2025-53786/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-53786
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-53786
- OSV: https://osv.dev/vulnerability/CVE-2025-53786

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-53786/
Summaries are generated and may contain mistakes; the official description above is the record.