Through a malicious URL that contained a quote character it was possible to inject HTML code in KMail's plaintext viewer. Due to the parser used on the URL it was not possible to include the equal sign (=) or a space into the injected HTML, which greatly reduces the available HTML functionality. Although it is possible to include an HTML comment indicator to hide content.
| Software | From | Fixed in |
|---|---|---|
| kde / kmail | - | 4.4.0.x |
| debian / debian_linux | 8.0 | 8.0.x |
| fedoraproject / fedora | 25 | 25.x |
| suse / linux_enterprise | 12.0 | 12.0.x |