The vulnerability arises from the {% attrs %} template tag in the slippers package, which concatenates untrusted context data directly into an HTML attribute string without escaping. This omission enables an attacker to break out of the attribute context and inject arbitrary HTML or JavaScript, potentially executing code in the victim’s browser.

Django applications that use the mixxorz slippers framework with any version prior to 0.6.3 are affected. The issue was fixed in slippers version 0.6.3, so projects still running older releases are at risk.

The CVSS score of 6.1 indicates moderate severity, and the exploit can be delivered via normal application traffic that supplies untrusted data to a template using {% attrs %}. No EPSS score is available and the vulnerability is not listed in the CISA KEV catalog, but the attack vector is straightforward: craft a malicious value for a context variable, causing the rendered page to include injected script or markup.