# CVE-2025-13909: Information Disclosure via Multi-Tenant Authentication Flows in WSO2 Identity Server Allows Cross-Tenant PII Exposure

> Attackers can expose personally identifiable information across tenants due to insufficient validation in multi-tenant authentication flows.

- **Severity:** Medium 4.3 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 6 Aug 2026
- **Updated:** 6 Aug 2026
- **Also known as:** GHSA-c5g7-4966-ghvv

## What is CVE-2025-13909?

CVE-2025-13909 is a medium-severity vulnerability in Wso2 Identity Server, published on 6 Aug 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

The system accepts authentication requests without sufficient validation to enforce tenant isolation when using Email OTP, SMS OTP, or Magic Link as first-factor authenticators. This failure to adequately separate user data between tenants can lead to the exposure of personally identifiable information.

Successful exploitation allows an attacker to disclose personally identifiable information of users in different tenants, resulting in privacy violations and potential regulatory non-compliance. This may include unauthorized access to user details such as mobile numbers.

Weakness: CWE-200 (Exposure of Sensitive Information to an Unauthorized Actor), CWE-20 (Improper Input Validation)

## Which versions are affected by CVE-2025-13909?

It affects 1 product.


Products: Wso2 Identity Server.

## How do I fix CVE-2025-13909?

No fix has been published for CVE-2025-13909 yet. Limit exposure of the affected software until one is available.

## Is CVE-2025-13909 being exploited?

There is no known exploitation of CVE-2025-13909 in the wild and no public exploit code.

## Other vulnerabilities in Wso2 Identity Server

- [CVE-2016-4311](https://insights.sbomify.com/CVE-2016-4311/): Cross-site request forgery in n/a (high 8.8)
- [CVE-2025-10470](https://insights.sbomify.com/CVE-2025-10470/): Denial-of-Service via Magic Link Authentication in WSO2 Identity Server Allows Service Unavailability (high 8.6)
- [CVE-2025-12107](https://insights.sbomify.com/CVE-2025-12107/): Server-Side Template Injection via Velocity Template Engine in Multiple WSO2 Products Allows Remote Code Execution (high 8.4)
- [CVE-2016-4312](https://insights.sbomify.com/CVE-2016-4312/): XML external entity in n/a (high 7.5)
- [CVE-2025-10908](https://insights.sbomify.com/CVE-2025-10908/): Account Lock Bypass via Magic Link or Pass Key Authentication in WSO2 Identity Server Allows Unauthorized Access (high 7.3)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-13909 and fix it if it is affected.

What it is: CVE-2025-13909 is a medium-severity vulnerability in Wso2 Identity Server, published on 6 Aug 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2025-13909 in the wild and no public exploit code.

Affected product: Wso2 Identity 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-2025-13909/ (Markdown: https://insights.sbomify.com/CVE-2025-13909/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-13909
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-13909
- OSV: https://osv.dev/vulnerability/CVE-2025-13909

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-13909/
Summaries are generated and may contain mistakes; the official description above is the record.