diff --git a/changelog.d/12887.misc b/changelog.d/12887.misc
new file mode 100644
index 0000000000..7f6f731832
--- /dev/null
+++ b/changelog.d/12887.misc
@@ -0,0 +1 @@
+Improve URL previews by not including the content of media tags in the generated description.
\ No newline at end of file
diff --git a/synapse/rest/media/v1/preview_html.py b/synapse/rest/media/v1/preview_html.py
index ca73965fc2..0358c68a64 100644
--- a/synapse/rest/media/v1/preview_html.py
+++ b/synapse/rest/media/v1/preview_html.py
@@ -246,7 +246,9 @@ def parse_html_description(tree: "etree.Element") -> Optional[str]:
Grabs any text nodes which are inside the <body/> tag, unless they are within
an HTML5 semantic markup tag (<header/>, <nav/>, <aside/>, <footer/>), or
- if they are within a <script/> or <style/> tag.
+ if they are within a <script/>, <svg/> or <style/> tag, or if they are within
+ a tag whose content is usually only shown to old browsers
+ (<iframe/>, <video/>, <canvas/>, <picture/>).
This is a very very very coarse approximation to a plain text render of the page.
@@ -268,6 +270,12 @@ def parse_html_description(tree: "etree.Element") -> Optional[str]:
"script",
"noscript",
"style",
+ "svg",
+ "iframe",
+ "video",
+ "canvas",
+ "img",
+ "picture",
etree.Comment,
)
|
