From 86bb2b176b149f6c1726027f26eb5fcccd5aa61b Mon Sep 17 00:00:00 2001
From: Todd Schiller <todd.schiller@gmail.com>
Date: Thu, 4 Jun 2026 17:19:46 -0400
Subject: [PATCH] Skip SVG text nodes in prompt-injection-redact (#133)

Injection-shaped text inside an inline SVG's <title>Codestin Search App</title>
+            <desc>${FIXTURES.OVERRIDE_GUARDRAILS}</desc>
+            <text>${FIXTURES.DISREGARD}</text>
+          </svg>
+        </div>
+      </article>
+    `;
+    promptInjectionRedactRule.apply(document.body);
+
+    expect(document.querySelector("article")).not.toBeNull();
+    expect(document.querySelector("h1")?.textContent).toBe(
+      "Product title that stays visible.",
+    );
+    expect(document.querySelector(`.${PLACEHOLDER_CLASS}`)).toBeNull();
+  });
+
   it("does not process text inside SCRIPT or STYLE", () => {
     document.body.innerHTML = `
       <script>${FIXTURES.SCRIPT_STRING}</script>
diff --git a/extension/src/rules/prompt-injection-redact.ts b/extension/src/rules/prompt-injection-redact.ts
index 59572ef..63552fd 100644
--- a/extension/src/rules/prompt-injection-redact.ts
+++ b/extension/src/rules/prompt-injection-redact.ts
@@ -54,7 +54,16 @@ function findContainer(textNode: Text): HTMLElement | null {
 
 function apply(root: ParentNode): void {
   const containers = new Set<HTMLElement>();
-  for (const node of walkTextNodes(root, { minLength: MIN_TEXT_LENGTH })) {
+  for (const node of walkTextNodes(root, {
+    minLength: MIN_TEXT_LENGTH,
+    // SVG <title>/<desc>/<text> are the injection carriers inside SVG, and
+    // `svg-text-strip` handles them by blanking the text in place. Letting
+    // prompt-injection-redact also fire on those text nodes is destructive:
+    // the SVG has no p/li/td ancestor, so `findContainer` escalates all the
+    // way up to the surrounding <article>/<section> and the entire product
+    // header gets replaced with a single placeholder (#133).
+    shouldSkipParent: (parent) => parent.closest("svg") !== null,
+  })) {
     if (!containsInjection(node.nodeValue ?? "")) {
       continue;
     }