311728 2026-04-08 06:41:10 -0700 Page CSP blocks content script background image rendering in action popups 2026-05-23 07:43:57 -0700 1 1 1 Unclassified WebKit WebKit Extensions Safari 26 Mac (Apple Silicon) macOS 26 NEW https://jeurissen.co/webext-demos/action-popup-content-script-css-data-image InRadar P2 Normal --- 1 carlosj-webkit-bugzilla webkit-unassigned timothy webkit-bug-importer oldest_to_newest 2197967 0 carlosj-webkit-bugzilla 2026-04-08 06:41:10 -0700 Given the following: Extension opens extension popup The popup has an iframe The iframe is set to a document which declares a CSP with default-src The extension applied a css content script to that document with a data:image based background-image Somehow Webkit does not render this image properly. While other engines render it completely fine. It seems somehow Webkit interprets the CSP as if it should block the css image. See demo extension: http://jeurissen.co/webext-demos/action-popup-content-script-css-data-image 2197968 1 webkit-bug-importer 2026-04-08 06:41:16 -0700 <rdar://problem/174316860>