diff --git a/server/lib/pathMatch.ts b/server/lib/pathMatch.ts
index a007f9ec3..8ef579607 100644
--- a/server/lib/pathMatch.ts
+++ b/server/lib/pathMatch.ts
@@ -15,10 +15,41 @@ function getSegmentRegex(patternPart: string): RegExp {
     return regex;
 }
 
+// Decodes percent-encoding (so an encoded slash like `%2F` is treated as a
+// real path separator, matching what most backends will do) and then
+// resolves `.` / `..` segments, so a request like `/public%2F..%2Fadmin/`
+// or `/public/../admin/` is matched as `/admin/`, not as a literal segment
+// or a wildcard-swallowed sequence under `/public/*`.
+function decodeAndResolvePath(p: string): string[] {
+    const rawParts = p.split("/").filter(Boolean);
+
+    const resolved: string[] = [];
+    for (const rawPart of rawParts) {
+        let part: string;
+        try {
+            part = decodeURIComponent(rawPart);
+        } catch {
+            part = rawPart;
+        }
+
+        // an encoded slash can turn one raw segment into several real ones
+        for (const segment of part.split("/").filter(Boolean)) {
+            if (segment === ".") {
+                continue;
+            } else if (segment === "..") {
+                resolved.pop();
+            } else {
+                resolved.push(segment);
+            }
+        }
+    }
+
+    return resolved;
+}
+
 export function isPathAllowed(pattern: string, path: string): boolean {
-    const normalize = (p: string) => p.split("/").filter(Boolean);
-    const patternParts = normalize(pattern);
-    const pathParts = normalize(path);
+    const patternParts = pattern.split("/").filter(Boolean);
+    const pathParts = decodeAndResolvePath(path);
 
     function matchSegments(
         patternIndex: number,
diff --git a/server/routers/badger/verifySession.test.ts b/server/routers/badger/verifySession.test.ts
index 681717f9c..c91805f8e 100644
--- a/server/routers/badger/verifySession.test.ts
+++ b/server/routers/badger/verifySession.test.ts
@@ -236,6 +236,38 @@ function runTests() {
         "Root path should not match non-root path"
     );
 
+    // Path traversal / encoded-slash bypass regression tests
+    assertEquals(
+        isPathAllowed("public/*", "public/../admin"),
+        false,
+        "Literal .. traversal out of an allowed prefix must not match"
+    );
+    assertEquals(
+        isPathAllowed("public/*", "public%2F..%2Fadmin"),
+        false,
+        "Encoded-slash traversal out of an allowed prefix must not match"
+    );
+    assertEquals(
+        isPathAllowed("public/*", "public%2f..%2fadmin%2ffile"),
+        false,
+        "Encoded-slash traversal is case-insensitively decoded before matching"
+    );
+    assertEquals(
+        isPathAllowed("admin/*", "public/../admin/secret"),
+        true,
+        ".. traversal INTO a restricted path should still be caught by its own rule"
+    );
+    assertEquals(
+        isPathAllowed("public/*", "public%2Ffoo"),
+        true,
+        "Encoded slash without traversal should still resolve and match normally"
+    );
+    assertEquals(
+        isPathAllowed("public/*", "public/./foo"),
+        true,
+        "Single-dot segments are a no-op and should not affect matching"
+    );
+
     console.log("All path matching tests passed!");
 }