Currently, all uses of -webkit-filter in a tag's style attribute are being replaced with "/* insecure input */". Assuming this is due to confusion with -ms-filter and there isn't any actual security risk in allowing -webkit-filter, the style should be allowed.
Version: 1.19
Severity: enhancement
This was resolved by https://phabricator.wikimedia.org/T308160. It is now possible to use -webkit-filter (although the unprefixed filter should be preferred anyway).
T308160: Uncensor use of "filter" CSS property on wikitext pages is about the wikitext parser. This issue is tagged as TemplateStyles (now, at least; presumably the task author meant the task to be about the parser, since it predates the existence of TemplateStyes). In TemplateStyles, this isn't resolved.
I'll just untag and close as duplicate to reduce confusion. Please file a dedicated task for TemplateStyles / css-sanitizer if you think this functionality is needed there.