# CVE-2026-91204: Apache Roller: Stored javascript: URI in HTML comments

> An attacker can inject malicious JavaScript via HTML comments in Apache Roller, leading to script execution in victim browsers when HTML comments are enabled.

- **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:** 28 Sep 2026
- **Updated:** 30 Sep 2026
- **Also known as:** GHSA-xg59-jgm4-xmq5

## What is CVE-2026-91204?

CVE-2026-91204 is a medium-severity cross-site scripting vulnerability in Apache Roller, published on 28 Sep 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 ('Cross-site Scripting') in Apache Roller 6.1.5 allows an anonymous remote attacker to store a comment containing a javascript: URI link that survives HTML comment formatting and can execute script in the browser of a visitor who clicks it. This affects only sites that enable HTML in comments (users.comments.htmlenabled=true) together with the HTMLSubset comment formatter; comment moderation, where enabled, delays publication. Users are recommended to upgrade to Apache Roller 6.1.6 or later, which restricts restored links to http, https and mailto URIs.

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

## Which versions are affected by CVE-2026-91204?


## How do I fix CVE-2026-91204?

No fix has been published for CVE-2026-91204 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-91204 being exploited?

There is no known exploitation of CVE-2026-91204 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-91204 and fix it if it is affected.

What it is: CVE-2026-91204 is a medium-severity cross-site scripting vulnerability in Apache Roller, published on 28 Sep 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-2026-91204 in the wild and no public exploit code.

Affected product: Apache Roller. 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-2026-91204/ (Markdown: https://insights.sbomify.com/CVE-2026-91204/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-91204
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-91204
- OSV: https://osv.dev/vulnerability/CVE-2026-91204

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-91204/
Summaries are generated and may contain mistakes; the official description above is the record.