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.
- 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
- None listed
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
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.
Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.
Is CVE-2026-91204 being exploited?
There is no known exploitation of CVE-2026-91204 in the wild and no public exploit code.
Sources
Also known as GHSA-xg59-jgm4-xmq5.