From da77125a7476fcb990ff6b9884a40c42cd439daf Mon Sep 17 00:00:00 2001
From: Robby <robbyczgw@gmail.com>
Date: Wed, 28 Jan 2026 10:52:23 +0000
Subject: [PATCH] security(memory): fix workspace escape via path prefix
 collision

Problem:
The workspace boundary check used `absPath.startsWith(this.workspaceDir)`.
If workspaceDir is `/root/work`, path `/root/workspace/secrets.txt` passes
because `/root/workspace` starts with `/root/work`.

Solution:
Use `path.relative()` instead:
```typescript
const rel = path.relative(this.workspaceDir, absPath);
if (rel.startsWith("..") || path.isAbsolute(rel)) {
  throw new Error("path escapes workspace");
}
```

This correctly detects the escape because `path.relative("/root/work", "/root/workspace")`
returns `"../workspace"`.

Fixes #3277 (partial)
[AI-assisted: lightly tested, code understood]
---
 src/memory/manager.ts | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/memory/manager.ts b/src/memory/manager.ts
index 9a9991d10..fa8493fb5 100644
--- a/src/memory/manager.ts
+++ b/src/memory/manager.ts
@@ -401,7 +401,8 @@ export class MemoryIndexManager {
       throw new Error("path required");
     }
     const absPath = path.resolve(this.workspaceDir, relPath);
-    if (!absPath.startsWith(this.workspaceDir)) {
+    const rel = path.relative(this.workspaceDir, absPath);
+    if (rel.startsWith("..") || path.isAbsolute(rel)) {
       throw new Error("path escapes workspace");
     }
     const content = await fs.readFile(absPath, "utf-8");