diff --git a/.changeset/dirty-pears-allow.md b/.changeset/dirty-pears-allow.md
new file mode 100644
index 0000000000..4b488ad79d
--- /dev/null
+++ b/.changeset/dirty-pears-allow.md
@@ -0,0 +1,5 @@
+---
+'@backstage/backend-common': patch
+---
+
+Added a second validation to the `dir()` method of ZIP archive responses returned from `readTree()` that ensures that extracted files do not fall outside the target directory.
diff --git a/packages/backend-common/src/reading/tree/ZipArchiveResponse.ts b/packages/backend-common/src/reading/tree/ZipArchiveResponse.ts
index 1a6658b0c2..4100af3d57 100644
--- a/packages/backend-common/src/reading/tree/ZipArchiveResponse.ts
+++ b/packages/backend-common/src/reading/tree/ZipArchiveResponse.ts
@@ -25,6 +25,7 @@ import {
   ReadTreeResponseFile,
 } from '../types';
 import { streamToBuffer } from './util';
+import { resolveSafeChildPath } from '../../paths';
 
 /**
  * Wraps a zip archive stream into a tree response reader.
@@ -187,10 +188,10 @@ export class ZipArchiveResponse implements ReadTreeResponse {
       const dirname = platformPath.dirname(entryPath);
 
       if (dirname) {
-        await fs.mkdirp(platformPath.join(dir, dirname));
+        await fs.mkdirp(resolveSafeChildPath(dir, dirname));
       }
       return new Promise(async (resolve, reject) => {
-        const file = fs.createWriteStream(platformPath.join(dir, entryPath));
+        const file = fs.createWriteStream(resolveSafeChildPath(dir, entryPath));
         file.on('finish', resolve);
 
         content.on('error', reject);