diff --git a/backend/src/app/media/svg.clj b/backend/src/app/media/svg.clj
index 1de52d4030..4cad562d91 100644
--- a/backend/src/app/media/svg.clj
+++ b/backend/src/app/media/svg.clj
@@ -52,30 +52,47 @@
 (def ^:private dangerous-attrs-pattern #"(?i)^on\w+$")
 (def ^:private javascript-href-pattern #"(?i)^javascript:")
 
+(def ^:private dangerous-tags
+  #{"script" "foreignObject" "set"
+    "animate" "animateTransform" "animateColor" "animateMotion"})
+
+(defn- local-name
+  "Return the local name of a parsed tag or attribute keyword.
+
+   The XML parser interns qualified names with the prefix included in
+   the keyword name and no keyword namespace: `<x:script>` parses as
+   the keyword `:x:script`. Dangerous elements and attributes behave
+   the same in the browser regardless of the prefix used, so matching
+   is done on the local name: the part after the last `:`."
+  [k]
+  (let [n (name k)]
+    (if (str/includes? n ":")
+      (last (str/split n ":"))
+      n)))
+
 (defn- sanitize-svg-element
   "Recursively sanitize an SVG element by removing dangerous tags and attributes."
   [{:keys [tag attrs content] :as element}]
   (when (and (map? element) tag)
-    (let [dangerous-tags #{:script :foreignObject :set :animate :animateTransform :animateColor :animateMotion}]
-      (when-not (contains? dangerous-tags tag)
-        (let [clean-attrs (->> attrs
-                               (remove (fn [[k v]]
-                                         (or (re-matches dangerous-attrs-pattern (name k))
-                                             (and (#{:href :xlink:href} k)
-                                                  (string? v)
-                                                  (re-find javascript-href-pattern (str/trim v))))))
-                               (into {}))
-              clean-content (when content
-                              (->> content
-                                   (filter #(or (string? %) (map? %)))
-                                   (map (fn [child]
-                                          (if (map? child)
-                                            (sanitize-svg-element child)
-                                            child)))
-                                   (filter some?)
-                                   vec))]
-          (cond-> {:tag tag :attrs clean-attrs}
-            (seq clean-content) (assoc :content clean-content)))))))
+    (when-not (contains? dangerous-tags (local-name tag))
+      (let [clean-attrs (->> attrs
+                             (remove (fn [[k v]]
+                                       (or (re-matches dangerous-attrs-pattern (local-name k))
+                                           (and (= "href" (local-name k))
+                                                (string? v)
+                                                (re-find javascript-href-pattern (str/trim v))))))
+                             (into {}))
+            clean-content (when content
+                            (->> content
+                                 (filter #(or (string? %) (map? %)))
+                                 (map (fn [child]
+                                        (if (map? child)
+                                          (sanitize-svg-element child)
+                                          child)))
+                                 (filter some?)
+                                 vec))]
+        (cond-> {:tag tag :attrs clean-attrs}
+          (seq clean-content) (assoc :content clean-content))))))
 
 (defn sanitize-svg
   "Sanitize SVG content by removing dangerous elements and attributes.
diff --git a/backend/test/backend_tests/media_test.clj b/backend/test/backend_tests/media_test.clj
index eb2f2517c7..3c3a887032 100644
--- a/backend/test/backend_tests/media_test.clj
+++ b/backend/test/backend_tests/media_test.clj
@@ -137,6 +137,72 @@
       (t/is (not (clojure.string/includes? result "onmouseover")))
       (t/is (clojure.string/includes? result "<rect")))))
 
+(t/deftest sanitize-svg-namespace-prefixed-script
+  (t/testing "sanitize-svg removes script tags written with a namespace prefix bound to the SVG namespace"
+    (let [svg "<svg xmlns=\"http://www.w3.org/2000/svg\" xmlns:x=\"http://www.w3.org/2000/svg\" width=\"100\" height=\"100\"><x:script>alert('xss')</x:script><rect width=\"50\" height=\"50\"/></svg>"
+          result (svg/sanitize-svg svg)]
+      (t/is (not (clojure.string/includes? result "<x:script")))
+      (t/is (not (clojure.string/includes? result "alert")))
+      (t/is (clojure.string/includes? result "<rect")))))
+
+(t/deftest sanitize-svg-arbitrary-prefixed-script
+  (t/testing "sanitize-svg removes script tags written with an arbitrary namespace prefix"
+    (let [svg "<svg xmlns=\"http://www.w3.org/2000/svg\" xmlns:p=\"http://www.w3.org/2000/svg\" width=\"100\" height=\"100\"><p:script>alert('xss')</p:script><rect width=\"50\" height=\"50\"/></svg>"
+          result (svg/sanitize-svg svg)]
+      (t/is (not (clojure.string/includes? result "<p:script")))
+      (t/is (not (clojure.string/includes? result "alert")))
+      (t/is (clojure.string/includes? result "<rect")))))
+
+(t/deftest sanitize-svg-nested-prefixed-script
+  (t/testing "sanitize-svg removes namespace-prefixed script tags from nested elements"
+    (let [svg "<svg xmlns=\"http://www.w3.org/2000/svg\" xmlns:x=\"http://www.w3.org/2000/svg\" width=\"100\" height=\"100\"><g><x:script>alert('xss')</x:script></g></svg>"
+          result (svg/sanitize-svg svg)]
+      (t/is (not (clojure.string/includes? result "<x:script")))
+      (t/is (not (clojure.string/includes? result "alert")))
+      (t/is (clojure.string/includes? result "<g")))))
+
+(t/deftest sanitize-svg-prefixed-dangerous-tags
+  (t/testing "sanitize-svg removes dangerous animation elements written with a namespace prefix"
+    (let [svg "<svg xmlns=\"http://www.w3.org/2000/svg\" xmlns:x=\"http://www.w3.org/2000/svg\" width=\"100\" height=\"100\"><x:foreignObject width=\"10\" height=\"10\"/><x:set attributeName=\"onmouseover\" to=\"alert('xss')\"/><x:animate attributeName=\"fill\" to=\"red\"/><x:animateTransform attributeName=\"transform\"/><rect width=\"50\" height=\"50\"/></svg>"
+          result (svg/sanitize-svg svg)]
+      (t/is (not (clojure.string/includes? result "foreignObject")))
+      (t/is (not (clojure.string/includes? result "<x:set")))
+      (t/is (not (clojure.string/includes? result "<x:animate")))
+      (t/is (not (clojure.string/includes? result "alert")))
+      (t/is (clojure.string/includes? result "<rect")))))
+
+(t/deftest sanitize-svg-prefixed-javascript-href
+  (t/testing "sanitize-svg removes javascript: URLs from href attributes written with a namespace prefix"
+    (let [svg "<svg xmlns=\"http://www.w3.org/2000/svg\" xmlns:x=\"http://www.w3.org/2000/svg\" width=\"100\" height=\"100\"><a x:href=\"javascript:alert('xss')\"><rect width=\"50\" height=\"50\"/></a></svg>"
+          result (svg/sanitize-svg svg)]
+      (t/is (not (clojure.string/includes? result "javascript:")))
+      (t/is (not (clojure.string/includes? result "alert")))
+      (t/is (clojure.string/includes? result "<a")))))
+
+(t/deftest sanitize-svg-prefixed-event-handlers
+  (t/testing "sanitize-svg removes event handler attributes written with a namespace prefix"
+    (let [svg "<svg xmlns=\"http://www.w3.org/2000/svg\" xmlns:x=\"http://www.w3.org/2000/svg\" width=\"100\" height=\"100\" x:onload=\"alert('xss')\"><rect width=\"50\" height=\"50\" x:onclick=\"alert('xss')\"/></svg>"
+          result (svg/sanitize-svg svg)]
+      (t/is (not (clojure.string/includes? result "onload")))
+      (t/is (not (clojure.string/includes? result "onclick")))
+      (t/is (not (clojure.string/includes? result "alert")))
+      (t/is (clojure.string/includes? result "<rect")))))
+
+(t/deftest sanitize-svg-prefixed-xlink-namespace-href
+  (t/testing "sanitize-svg removes javascript: URLs from href written with a prefix bound to the xlink namespace"
+    (let [svg "<svg xmlns=\"http://www.w3.org/2000/svg\" xmlns:y=\"http://www.w3.org/1999/xlink\" width=\"100\" height=\"100\"><a y:href=\"javascript:alert('xss')\"><rect width=\"50\" height=\"50\"/></a></svg>"
+          result (svg/sanitize-svg svg)]
+      (t/is (not (clojure.string/includes? result "javascript:")))
+      (t/is (not (clojure.string/includes? result "alert")))
+      (t/is (clojure.string/includes? result "<a")))))
+
+(t/deftest sanitize-svg-preserved-prefixed-attrs
+  (t/testing "sanitize-svg preserves legitimate attributes written with a namespace prefix"
+    (let [svg "<svg xmlns=\"http://www.w3.org/2000/svg\" xmlns:xml=\"http://www.w3.org/XML/1998/namespace\"><text xml:space=\"preserve\">hola</text></svg>"
+          result (svg/sanitize-svg svg)]
+      (t/is (clojure.string/includes? result "xml:space"))
+      (t/is (clojure.string/includes? result "hola")))))
+
 (t/deftest info-invalid-image
   (t/testing "info on invalid image raises error"
     (let [path (fs/create-tempfile :prefix "penpot-test-" :suffix ".jpg")]