In uBlock before 0.9.5.15, the $rewrite filter option allows filter-list maintainers to run arbitrary code in a client-side session when a web service loads a script for execution using XMLHttpRequest or Fetch, and the script origin has an open redirect.

uBlock Origin before 1.36.2 and nMatrix before 4.4.9 support an arbitrary depth of parameter nesting for strict blocking, which allows crafted web sites to cause a denial of service (unbounded recursion that can trigger memory consumption and a loss of all blocking functionality).

A vulnerability was found in gorhill uBlock Origin up to 1.63.3b16. It has been classified as problematic. Affected is the function currentStateChanged of the file src/js/1p-filters.js of the component UI. The manipulation leads to inefficient regular expression complexity. It is possible to launch the attack remotely. The complexity of an attack is rather high. The exploitability is told to be difficult. The exploit has been disclosed to the public and may be used. Upgrading to version 1.63.3b17 is able to address this issue. The patch is identified as eaedaf5b10d2f7857c6b77fbf7d4a80681d4d46c. It is recommended to upgrade the affected component.