# CVE-2026-11854: Cross-Site Scripting via Authentication Endpoint Error Message in Multiple WSO2 Products


- **Severity:** Medium 6.1 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N`)
- **Exploited in the wild:** Not known
- **Fix available:** No
- **Published:** 28 Oct 2026
- **Updated:** 29 Oct 2026
- **Also known as:** GHSA-jw6g-mv47-3fhf

## What is CVE-2026-11854?

CVE-2026-11854 is a medium-severity vulnerability in WSO2 API Control Plane, published on 28 Oct 2026. 

### Official description

The authentication endpoint generates an error message that includes reflected data directly from the request without sufficient sanitization or encoding. This allows an attacker to inject malicious scripts that can be executed in the context of a victim's browser.

Successful exploitation enables an attacker to perform actions within the user's browser, such as redirecting the user to a malicious website, modifying the web page's user interface, or retrieving information. However, due to the httpOnly flag on session-related cookies, session hijacking or similar attacks are not possible.

Weakness: CWE-79 (Improper Neutralization of Input During Web Page Generation)

## Which versions are affected by CVE-2026-11854?


## How do I fix CVE-2026-11854?

No fix has been published for CVE-2026-11854 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-11854 being exploited?

There is no known exploitation of CVE-2026-11854 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-11854 and fix it if it is affected.

What it is: CVE-2026-11854 is a medium-severity vulnerability in WSO2 API Control Plane, published on 28 Oct 2026. 
Exploitation: There is no known exploitation of CVE-2026-11854 in the wild and no public exploit code.

Affected product: WSO2 API Control Plane. 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-2026-11854/ (Markdown: https://insights.sbomify.com/CVE-2026-11854/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-11854
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-11854
- OSV: https://osv.dev/vulnerability/CVE-2026-11854

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-11854/
Summaries are generated and may contain mistakes; the official description above is the record.