diff --git a/components/script/dom/document.rs b/components/script/dom/document.rs
index 68efa07537c..a83629b4046 100644
--- a/components/script/dom/document.rs
+++ b/components/script/dom/document.rs
@@ -4299,7 +4299,14 @@ impl Document {
     }
 
     pub(crate) fn set_csp_list(&self, csp_list: Option<CspList>) {
-        self.policy_container.borrow_mut().set_csp_list(csp_list);
+        if let Some(new_list) = csp_list {
+            let mut current = self.get_csp_list();
+            match current {
+                Some(ref mut existing) => existing.append(new_list),
+                None => current = Some(new_list),
+            }
+            self.policy_container.borrow_mut().set_csp_list(current);
+        }
     }
 
     pub(crate) fn get_csp_list(&self) -> Option<CspList> {
diff --git a/components/script/dom/htmlheadelement.rs b/components/script/dom/htmlheadelement.rs
index 7b2d715318f..9289163a195 100644
--- a/components/script/dom/htmlheadelement.rs
+++ b/components/script/dom/htmlheadelement.rs
@@ -2,19 +2,15 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
 
-use content_security_policy::{CspList, PolicyDisposition, PolicySource};
 use dom_struct::dom_struct;
-use html5ever::{LocalName, Prefix, local_name, ns};
+use html5ever::{LocalName, Prefix};
 use js::rust::HandleObject;
 
-use crate::dom::bindings::codegen::Bindings::DocumentBinding::DocumentMethods;
 use crate::dom::bindings::inheritance::Castable;
 use crate::dom::bindings::root::DomRoot;
 use crate::dom::document::Document;
-use crate::dom::element::Element;
 use crate::dom::htmlelement::HTMLElement;
-use crate::dom::htmlmetaelement::HTMLMetaElement;
-use crate::dom::node::{BindContext, Node, NodeTraits, ShadowIncluding};
+use crate::dom::node::{BindContext, Node};
 use crate::dom::userscripts::load_script;
 use crate::dom::virtualmethods::VirtualMethods;
 use crate::script_runtime::CanGc;
@@ -53,48 +49,6 @@ impl HTMLHeadElement {
         n.upcast::<Node>().set_weird_parser_insertion_mode();
         n
     }
-
-    /// <https://html.spec.whatwg.org/multipage/#attr-meta-http-equiv-content-security-policy>
-    pub(crate) fn set_content_security_policy(&self) {
-        let doc = self.owner_document();
-
-        if doc.GetHead().as_deref() != Some(self) {
-            return;
-        }
-
-        let mut csp_list: Option<CspList> = None;
-        let node = self.upcast::<Node>();
-        let candidates = node
-            .traverse_preorder(ShadowIncluding::No)
-            .filter_map(DomRoot::downcast::<Element>)
-            .filter(|elem| elem.is::<HTMLMetaElement>())
-            .filter(|elem| {
-                elem.get_string_attribute(&local_name!("http-equiv"))
-                    .to_ascii_lowercase() ==
-                    *"content-security-policy"
-            })
-            .filter(|elem| {
-                elem.get_attribute(&ns!(), &local_name!("content"))
-                    .is_some()
-            });
-
-        for meta in candidates {
-            if let Some(ref content) = meta.get_attribute(&ns!(), &local_name!("content")) {
-                let content = content.value();
-                let content_val = content.trim();
-                if !content_val.is_empty() {
-                    let policies =
-                        CspList::parse(content_val, PolicySource::Meta, PolicyDisposition::Enforce);
-                    match csp_list {
-                        Some(ref mut csp_list) => csp_list.append(policies),
-                        None => csp_list = Some(policies),
-                    }
-                }
-            }
-        }
-
-        doc.set_csp_list(csp_list);
-    }
 }
 
 impl VirtualMethods for HTMLHeadElement {
diff --git a/components/script/dom/htmlmetaelement.rs b/components/script/dom/htmlmetaelement.rs
index e94a5e1ff33..875d790c60c 100644
--- a/components/script/dom/htmlmetaelement.rs
+++ b/components/script/dom/htmlmetaelement.rs
@@ -2,6 +2,7 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
 
+use content_security_policy::{CspList, PolicyDisposition, PolicySource};
 use dom_struct::dom_struct;
 use html5ever::{LocalName, Prefix, local_name, ns};
 use js::rust::HandleObject;
@@ -118,12 +119,47 @@ impl HTMLMetaElement {
     /// <https://html.spec.whatwg.org/multipage/#attr-meta-http-equiv-content-security-policy>
     fn apply_csp_list(&self) {
         if let Some(parent) = self.upcast::<Node>().GetParentElement() {
-            if let Some(head) = parent.downcast::<HTMLHeadElement>() {
-                head.set_content_security_policy();
+            if parent.downcast::<HTMLHeadElement>().is_some() {
+                self.set_content_security_policy();
             }
         }
     }
 
+    /// <https://html.spec.whatwg.org/multipage/#attr-meta-http-equiv-content-security-policy>
+    pub(crate) fn set_content_security_policy(&self) {
+        let doc = self.owner_document();
+
+        let meta_element = self.upcast::<Element>();
+
+        if meta_element
+            .get_string_attribute(&local_name!("http-equiv"))
+            .to_ascii_lowercase() !=
+            *"content-security-policy" ||
+            meta_element
+                .get_attribute(&ns!(), &local_name!("content"))
+                .is_none()
+        {
+            return;
+        }
+
+        let mut csp_list: Option<CspList> = None;
+
+        if let Some(ref content) = meta_element.get_attribute(&ns!(), &local_name!("content")) {
+            let content = content.value();
+            let content_val = content.trim();
+            if !content_val.is_empty() {
+                let policies =
+                    CspList::parse(content_val, PolicySource::Meta, PolicyDisposition::Enforce);
+                match csp_list {
+                    Some(ref mut csp_list) => csp_list.append(policies),
+                    None => csp_list = Some(policies),
+                }
+            }
+        }
+
+        doc.set_csp_list(csp_list);
+    }
+
     /// <https://html.spec.whatwg.org/multipage/#shared-declarative-refresh-steps>
     fn declarative_refresh(&self) {
         if !self.upcast::<Node>().is_in_a_document_tree() {
diff --git a/components/script/dom/servoparser/mod.rs b/components/script/dom/servoparser/mod.rs
index 9e45124522a..fa55545aecd 100644
--- a/components/script/dom/servoparser/mod.rs
+++ b/components/script/dom/servoparser/mod.rs
@@ -821,15 +821,7 @@ impl ParserContext {
         let Some(parser) = self.parser.as_ref().map(|p| p.root()) else {
             return;
         };
-        let new_csp_list = match parser.document.get_csp_list() {
-            None => parent_csp_list.clone(),
-            Some(original_csp_list) => {
-                let mut appended_csp_list = original_csp_list.clone();
-                appended_csp_list.append(parent_csp_list.clone());
-                appended_csp_list.to_owned()
-            },
-        };
-        parser.document.set_csp_list(Some(new_csp_list));
+        parser.document.set_csp_list(Some(parent_csp_list.clone()));
     }
 }
 
diff --git a/tests/wpt/meta/MANIFEST.json b/tests/wpt/meta/MANIFEST.json
index deff780986e..91f9258c508 100644
--- a/tests/wpt/meta/MANIFEST.json
+++ b/tests/wpt/meta/MANIFEST.json
@@ -397319,6 +397319,10 @@
       "062d823228a0bad1ed84fc432a262501e11a7d79",
       []
      ],
+     "meta-append-header.html.headers": [
+      "85de8bd415def35ca45c0abf74590cdfa393d0f4",
+      []
+     ],
      "meta-outside-head.sub.html.sub.headers": [
       "8e90073147a233a74727a3ba03307c1564dc3224",
       []
@@ -572954,6 +572958,13 @@
        {}
       ]
      ],
+     "meta-append-header.html": [
+      "2b95e92fdb72b54b716ac51196acc93afab17f92",
+      [
+       null,
+       {}
+      ]
+     ],
      "meta-img-src.html": [
       "bc7ffd66a70d78c4ae9f2cc19f8c2df70914243d",
       [
@@ -572968,6 +572979,13 @@
        {}
       ]
      ],
+     "meta-multiple-csp.html": [
+      "f09ead7f3e7588f88aadda68e72b1c9362d59910",
+      [
+       null,
+       {}
+      ]
+     ],
      "meta-outside-head.sub.html": [
       "7a706c2fc5f5d21b76e7f62f224c3ff74c80ba79",
       [
diff --git a/tests/wpt/tests/content-security-policy/meta/meta-append-header.html b/tests/wpt/tests/content-security-policy/meta/meta-append-header.html
new file mode 100644
index 00000000000..2b95e92fdb7
--- /dev/null
+++ b/tests/wpt/tests/content-security-policy/meta/meta-append-header.html
@@ -0,0 +1,32 @@
+<!DOCTYPE html>
+<meta http-equiv="Content-Security-Policy" content="img-src 'none'">
+<script nonce="abc" src="/resources/testharness.js"></script>
+<script nonce="abc" src="/resources/testharnessreport.js"></script>
+
+<body>
+  <script nonce="abc">
+    promise_test(t => {
+      return new Promise((resolve, reject) => {
+        const img = document.createElement("img");
+        img.src = "/content-security-policy/support/fail.png";
+
+        img.onload = () => reject("Image loaded unexpectedly");
+        img.onerror = (e) => resolve()
+
+        document.body.appendChild(img);
+      });
+    }, "dynamic img-src is blocked by meta CSP");
+
+    promise_test(t => {
+      return new Promise((resolve, reject) => {
+        const script = document.createElement("script");
+        script.src = "../resources/ran.js";
+
+        script.onload = () => reject("Script executed unexpectedly");
+        script.onerror = () => resolve();
+
+        document.body.appendChild(script);
+      });
+    }, "script without `abc` nonce is blocked by header CSP");
+  </script>
+</body>
diff --git a/tests/wpt/tests/content-security-policy/meta/meta-append-header.html.headers b/tests/wpt/tests/content-security-policy/meta/meta-append-header.html.headers
new file mode 100644
index 00000000000..85de8bd415d
--- /dev/null
+++ b/tests/wpt/tests/content-security-policy/meta/meta-append-header.html.headers
@@ -0,0 +1 @@
+Content-Security-Policy: script-src 'nonce-abc'
diff --git a/tests/wpt/tests/content-security-policy/meta/meta-multiple-csp.html b/tests/wpt/tests/content-security-policy/meta/meta-multiple-csp.html
new file mode 100644
index 00000000000..f09ead7f3e7
--- /dev/null
+++ b/tests/wpt/tests/content-security-policy/meta/meta-multiple-csp.html
@@ -0,0 +1,33 @@
+<!DOCTYPE html>
+<meta http-equiv="Content-Security-Policy" content="script-src 'nonce-abc'">
+<meta http-equiv="Content-Security-Policy" content="img-src 'none'">
+<script nonce="abc" src="/resources/testharness.js"></script>
+<script nonce="abc" src="/resources/testharnessreport.js"></script>
+
+<body>
+  <script nonce="abc">
+    promise_test(t => {
+      return new Promise((resolve, reject) => {
+        const img = document.createElement("img");
+        img.src = "/content-security-policy/support/fail.png";
+
+        img.onload = () => reject("Image loaded unexpectedly");
+        img.onerror = (e) => resolve()
+
+        document.body.appendChild(img);
+      });
+    }, "dynamic img-src is blocked by meta CSP");
+
+    promise_test(t => {
+      return new Promise((resolve, reject) => {
+        const script = document.createElement("script");
+        script.src = "../resources/ran.js";
+
+        script.onload = () => reject("Script executed unexpectedly");
+        script.onerror = () => resolve();
+
+        document.body.appendChild(script);
+      });
+    }, "script without `abc` nonce is blocked by meta CSP");
+  </script>
+</body>