CVE-2026-76984 Apache Wicket: XSS in MetaDataHeaderItem via addTagAttribute
An attacker can inject malicious scripts via improperly escaped attribute values in MetaDataHeaderItem, leading to cross-site scripting attacks.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2026-76984?
CVE-2026-76984 is a medium-severity cross-site scripting vulnerability in Apache Wicket, published on 31 Aug 2026. Any signed-in user can exploit it over the network, 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.head.MetaDataHeaderItem generates <meta> and <link> header tags. It escaped the attribute names it wrote, but ran the attribute values through a replacement of " with \". A backslash before a double quote means nothing in HTML, so a value containing a double quote ends its own attribute and what follows is parsed as further attributes of the generated tag.
An application is affected where it supplies an attribute value holding data an attacker can influence, through addTagAttribute or the forMetaTag and forLinkTag factory methods. A value may be given as an IModel, so it is not necessarily a literal.
There is no setting to change; an application can only avoid supplying a value that contains a double quote. Note that these values have never been escaped effectively: before the change released in 6.24.0, 7.4.0 and 8.0.0 they were written with no escaping at all.
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 6.17.0 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
Which versions are affected by CVE-2026-76984?
It affects 1 product.
Products include Apache Wicket.
How do I fix CVE-2026-76984?
No fix has been published for CVE-2026-76984 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-2026-76984 being exploited?
There is no known exploitation of CVE-2026-76984 in the wild and no public exploit code.
Other vulnerabilities in Apache Wicket
- CVE-2024-36522 Apache Wicket: Remote code execution via XSLT injection
- CVE-2026-40010 Apache Wicket: possible session fixation using AuthenticatedWebSession
- CVE-2016-6793 Deserialization in n/a
- CVE-2016-6806 Apache Wicket vulnerable to CSRF attacks
- CVE-2026-71257 Apache Wicket: Configured file upload limits are not enforced when the multipart request has already been parsed
Sources
Also known as GHSA-f53h-v4wv-fq5x.