diff --git a/auditor/checks/kimi_architect.ts b/auditor/checks/kimi_architect.ts
index c5562fa..b490889 100644
--- a/auditor/checks/kimi_architect.ts
+++ b/auditor/checks/kimi_architect.ts
@@ -364,7 +364,21 @@ async function computeGrounding(findings: Finding[]): Promise<{ total: number; v
     const [, relpath, lineStr] = m;
     const line = Number(lineStr);
     if (!line || !relpath) return false;
-    const abs = relpath.startsWith("/") ? relpath : resolve(REPO_ROOT, relpath);
+
+    // Path-traversal guard (caught 2026-04-27 by Kimi self-audit on
+    // dd77632). A model output emitting `../../../etc/passwd:1` would
+    // otherwise resolve outside REPO_ROOT and we'd readFile() a system
+    // file. Resolve, then verify the absolute path is anchored under
+    // REPO_ROOT — refuse anything that escapes (relative ".." traversal
+    // OR an absolute path that doesn't start with REPO_ROOT). Existing
+    // grounding-citation conventions all use repo-relative paths, so
+    // this rejection is safe in practice.
+    const abs = resolve(REPO_ROOT, relpath);
+    if (!abs.startsWith(REPO_ROOT + "/") && abs !== REPO_ROOT) {
+      f.evidence.push(`[grounding: path escapes repo root, refusing]`);
+      return false;
+    }
+
     if (!existsSync(abs)) {
       f.evidence.push("[grounding: file not found]");
       return false;