diff --git a/files/en-us/mozilla/firefox/releases/139/index.md b/files/en-us/mozilla/firefox/releases/139/index.md
index 963dfe1edd75e74..2c9eefa952a09aa 100644
--- a/files/en-us/mozilla/firefox/releases/139/index.md
+++ b/files/en-us/mozilla/firefox/releases/139/index.md
@@ -79,6 +79,9 @@ These features are newly shipped in Firefox 139 but are disabled by default. To
 - **Support for escaping `<` and `>` in attributes when serializing HTML**: `dom.security.html_serialization_escape_lt_gt`.
   Firefox now replaces the `<` and `>` characters with `&lt;` and `&gt;`, respectively, in attributes when serializing HTML. This helps prevent certain exploits where HTML is serialized and then injected back into the DOM.
   The affected methods and properties are: {{domxref("Element.innerHTML")}}, {{domxref("Element.outerHTML")}}, {{domxref("Element.getHTML()")}}, {{domxref("ShadowRoot.innerHTML")}}, and {{domxref("ShadowRoot.getHTML()")}}. ([Firefox bug 1941347](https://bugzil.la/1941347)).
+- **Disable non-standard `beforescriptexecute` and `afterscriptexecute`**: `dom.events.script_execute.enabled`.
+  The events have been disabled on Nightly only, allowing browser testing prior to their removal.
+  The affected events are: [`beforescriptexecute`](/en-US/docs/Web/API/Document/beforescriptexecute_event) and [`afterscriptexecute`](/en-US/docs/Web/API/Document/afterscriptexecute_event) on the {{domxref("Document")}} interface, and [`afterscriptexecute`](/en-US/docs/Web/API/Element/afterscriptexecute_event) and [`beforescriptexecute`](/en-US/docs/Web/API/Element/beforescriptexecute_event) on the {{domxref("Element")}} interface. ([Firefox bug 1954685](https://bugzil.la/1954685)).
 
 ## Older versions