CVE-2026-83539
What it is
Improper neutralization of input during web page generation in Apache Wicket. org.apache.wicket.extensions.markup.html.basic.SmartLinkLabel and org.apache.wicket.extensions.markup.html.basic.SmartLinkMultiLineLabel display a text value and turn any URL they find in it into a hyperlink. Both escape the model value and then hand the escaped text to org.apache.wicket.extensions.markup.html.basic.DefaultLinkParser, which searches it for anything of the form scheme://rest and wraps each match in an anchor whose href is the matched text, copied in as it is. The pattern accepts any scheme, and there is no list of permitted schemes anywhere on the path. A text value naming a scheme that executes script therefore becomes an anchor that executes it, in the application's origin and in the reader's own session, when the reader clicks the link. Rendering the page is not enough on its own; the link has to be activated. Escaping does not prevent this and is not the issue: the characters the payload needs are all valid in a URL and are ones that org.apache.wicket.util.string.Strings#escapeMarkup() leaves alone, and the value ends up in a URL rather than in element text, which is a context that escaping model data does not make safe. An application is affected where it renders text it received through either of these two components. That is what they are for: they exist to linkify email addresses and web URLs found in the data an application is displaying, so untrusted input is the purpose of the feature rather than a misuse of it, and no unusual configuration is involved. No other component uses this parser, and an application that uses neither SmartLinkLabel nor SmartLinkMultiLineLabel is not affected. On 9.x and 10.x the Content-Security-Policy Wicket sends by default admits script only from a source carrying a per-response nonce, and a URL whose scheme executes script cannot carry one, so that default policy stops the script from running. This is a property of the default policy and not of these components. An application that has weakened or disabled its Content-Security-Policy, for this or for any unrelated reason, is affected in full. Wicket 8.x has no Content-Security-Policy support at all and is affected as it stands. This issue affects Apache Wicket: from 8.0.0 through 8.19.0, from 9.0.0 through 9.24.0, from 10.0.0 through 10.11.0. Users of Apache Wicket 7.x or older, which are no longer supported, should upgrade to a supported version. Users are recommended to upgrade to version 8.20.0, 9.25.0 or 10.12.0, which fix the issue.
At a glance
- Exploitability
- Can be exploited over the network without logging in, but needs a user to act. High risk of data exposure, data tampering.
- Exploit odds
- 0.3% chance of exploitation in the next 30 days (EPSS).
- Fix
- A patch, advisory or fixed version is referenced. Upgrade or apply it.
Timeline
- ReservedThe CVE id was reserved by its CNA
- PublishedDisclosed publicly on CVE.org and NVD
- Last updatedMost recent change to the record
Why it ranks here
- Exploited in the wild: no, CISA does not list it.
- Exploit odds: 0.3% in the next 30 days (EPSS).
- Severity: 7.4 HIGH (CVSS).
- Fix: a patch or advisory is linked.
Details
- Published
- Last modified
- Exploit probability
- 0.3% · EPSS, next 30 days
- Weakness
- CWE-79 · Cross-site scripting
- Record status
- Deferred
Attack profile CVSS 4.0 · 7.4
- Attack vector
- Network
- Complexity
- Low
- Attack requirements
- Present
- Privileges needed
- None
- User interaction
- Active
- Confidentiality
- High
- Integrity
- High
- Availability
- None
Raw vector
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Is it in your code?
Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.
Read https://cve-list.com/agent/cve/CVE-2026-83539.md and follow it. Check whether this project is affected by CVE-2026-83539. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.
