diff --git a/static/js/documentLibrary.js b/static/js/documentLibrary.js
index da906b0..0341594 100644
--- a/static/js/documentLibrary.js
+++ b/static/js/documentLibrary.js
@@ -76,6 +76,15 @@ function _hlSearch(text) {
                        '<mark class="doclib-search-hl">$1</mark>');
   } catch { return esc; }
 }
+
+function _safeResearchHref(raw) {
+  try {
+    const parsed = new URL(String(raw || '').trim(), window.location.origin);
+    if (parsed.protocol === 'http:' || parsed.protocol === 'https:') return _esc(parsed.href);
+  } catch {}
+  return '';
+}
+
 let _libraryEscHandler = null;
 let _librarySelectMode = false;
 let _librarySelectedIds = new Set();
@@ -2649,7 +2658,7 @@ let _libraryArchivedView = false;   // Documents tab showing archived docs?
         const data = await res.json();
         _researchItems = data.research || data || [];
       } catch (e) {
-        grid.innerHTML = `<div class="hwfit-loading">Failed to load: ${e.message}</div>`;
+        grid.innerHTML = `<div class="hwfit-loading">Failed to load: ${_esc(e.message)}</div>`;
         return;
       }
       _renderResearchGrid();
@@ -2691,9 +2700,9 @@ let _libraryArchivedView = false;   // Documents tab showing archived docs?
       const sources = Array.isArray(detail.sources) ? detail.sources : [];
       const sourcesList = sources.slice(0, 12).map((src, i) => {
         const title = _esc(src.title || src.url || `Source ${i + 1}`);
-        const url = src.url || '';
+        const url = _safeResearchHref(src.url);
         return url
-          ? `<li><a href="${_esc(url)}" target="_blank" rel="noopener">${title}</a></li>`
+          ? `<li><a href="${url}" target="_blank" rel="noopener">${title}</a></li>`
           : `<li>${title}</li>`;
       }).join('');
       const sourcesHtml = sources.length
diff --git a/static/js/research/panel.js b/static/js/research/panel.js
index 6893ec2..d515580 100644
--- a/static/js/research/panel.js
+++ b/static/js/research/panel.js
@@ -1103,8 +1103,10 @@ function _renderResult(job) {
     html += '<div class="research-job-sources">';
     for (const s of job.sources.slice(0, 10)) {
       const title = _esc(s.title || s.url || '');
-      const url = _esc(s.url || '');
-      html += `<a href="${url}" target="_blank" rel="noopener" class="research-source-link">${title}</a>`;
+      const url = _safeSourceHref(s.url);
+      html += url
+        ? `<a href="${url}" target="_blank" rel="noopener" class="research-source-link">${title}</a>`
+        : `<span class="research-source-link">${title}</span>`;
     }
     if (job.sources.length > 10) html += `<span class="research-source-more">+${job.sources.length - 10} more</span>`;
     html += '</div>';
@@ -1231,3 +1233,11 @@ function _esc(s) {
   d.textContent = s || '';
   return d.innerHTML;
 }
+
+function _safeSourceHref(raw) {
+  try {
+    const parsed = new URL(String(raw || '').trim(), window.location.origin);
+    if (parsed.protocol === 'http:' || parsed.protocol === 'https:') return _esc(parsed.href);
+  } catch {}
+  return '';
+}
diff --git a/tests/test_research_source_link_xss.py b/tests/test_research_source_link_xss.py
new file mode 100644
index 0000000..e4cf0d8
--- /dev/null
+++ b/tests/test_research_source_link_xss.py
@@ -0,0 +1,26 @@
+"""Regression guards for API-provided research source hrefs."""
+
+from pathlib import Path
+
+
+_REPO = Path(__file__).resolve().parent.parent
+
+
+def test_document_library_research_preview_whitelists_source_hrefs():
+    src = (_REPO / "static" / "js" / "documentLibrary.js").read_text(encoding="utf-8")
+
+    assert "function _safeResearchHref(raw)" in src
+    assert "parsed.protocol === 'http:' || parsed.protocol === 'https:'" in src
+    assert "const url = _safeResearchHref(src.url);" in src
+    assert 'href="${_esc(url)}"' not in src
+    assert "Failed to load: ${_esc(e.message)}" in src
+    assert "Failed to load: ${e.message}" not in src
+
+
+def test_research_panel_whitelists_source_hrefs():
+    src = (_REPO / "static" / "js" / "research" / "panel.js").read_text(encoding="utf-8")
+
+    assert "function _safeSourceHref(raw)" in src
+    assert "parsed.protocol === 'http:' || parsed.protocol === 'https:'" in src
+    assert "const url = _safeSourceHref(s.url);" in src
+    assert 'const url = _esc(s.url || \'\');' not in src