# CVE-2026-76986: Apache Wicket: XSS in AbstractSingleSelectChoice via getNullValidDisplayValue

> Cross-site scripting in Apache Wicket allows attackers to inject scripts if developers override specific display value methods with unescaped user input.

- **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
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 31 Aug 2026
- **Updated:** 31 Aug 2026
- **Also known as:** GHSA-693x-mfgg-48mq

## What is CVE-2026-76986?

CVE-2026-76986 is a medium-severity cross-site scripting vulnerability in Apache Wicket, published on 31 Aug 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

Improper neutralization of input during web page generation in Apache Wicket.

org.apache.wicket.markup.html.form.AbstractSingleSelectChoice, the base class of DropDownChoice, writes the body of the default option — the entry shown when no choice is selected — into the markup as it is, while every other option body in the same select is escaped according to the escape-model-strings setting. The body comes from getNullValidDisplayValue() or getNullKeyDisplayValue(), both of which are protected, so what they return is not necessarily the plain text the default implementation reads from a resource bundle.

An application is affected where it overrides one of those methods and returns a value holding data an attacker can influence, or where its own nullValid or null bundle entry holds such a value. The bundles shipped with Wicket contain plain text. RadioChoice overrides getDefaultChoice to emit no default option and is not affected.

As a workaround, escape the value in the override.

This issue affects Apache Wicket: from 8.0.0 through 8.18.0, from 9.0.0 through 9.23.0, from 10.0.0 through 10.10.0. Older, unsupported releases from 1.5.0 onwards are also affected. Users are recommended to upgrade to version 8.19.0, 9.24.0 or 10.11.0, which fix the issue.

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

## Which versions are affected by CVE-2026-76986?

It affects 1 product.


Products: Apache Wicket.

## How do I fix CVE-2026-76986?

No fix has been published for CVE-2026-76986 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-76986 being exploited?

There is no known exploitation of CVE-2026-76986 in the wild and no public exploit code.

## Other vulnerabilities in Apache Wicket

- [CVE-2024-36522](https://insights.sbomify.com/CVE-2024-36522/): Apache Wicket: Remote code execution via XSLT injection (critical 9.8)
- [CVE-2026-40010](https://insights.sbomify.com/CVE-2026-40010/): Apache Wicket: possible session fixation using AuthenticatedWebSession (critical 9.1)
- [CVE-2016-6793](https://insights.sbomify.com/CVE-2016-6793/): Deserialization in n/a (critical 9.1)
- [CVE-2016-6806](https://insights.sbomify.com/CVE-2016-6806/): Apache Wicket vulnerable to CSRF attacks (high 8.8)
- [CVE-2026-71257](https://insights.sbomify.com/CVE-2026-71257/): Apache Wicket: Configured file upload limits are not enforced when the multipart request has already been parsed (high 7.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-76986 and fix it if it is affected.

What it is: CVE-2026-76986 is a medium-severity cross-site scripting vulnerability in Apache Wicket, published on 31 Aug 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2026-76986 in the wild and no public exploit code.

Affected product: Apache Wicket. 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-2026-76986/ (Markdown: https://insights.sbomify.com/CVE-2026-76986/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-76986
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-76986
- OSV: https://osv.dev/vulnerability/CVE-2026-76986

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-76986/
Summaries are generated and may contain mistakes; the official description above is the record.