diff --git a/changelog/+gitrepo-shared-access.added.md b/changelog/+gitrepo-shared-access.added.md
new file mode 100644
index 000000000..4725cc5b2
--- /dev/null
+++ b/changelog/+gitrepo-shared-access.added.md
@@ -0,0 +1 @@
+Add the `shared` option to `GitRepo` in `infrahub_sdk.testing.repository`. With `shared=True`, every user on the machine can read and write the Git repository that `GitRepo` creates, so Infrahub containers that run as another user than the test process can fetch from it and push to it. The default, `False`, keeps the current behavior.
diff --git a/infrahub_sdk/testing/repository.py b/infrahub_sdk/testing/repository.py
index 941f118ee..0bd67e711 100644
--- a/infrahub_sdk/testing/repository.py
+++ b/infrahub_sdk/testing/repository.py
@@ -1,6 +1,7 @@
 from __future__ import annotations
 
 import asyncio
+import os
 import shutil
 from dataclasses import dataclass, field
 from enum import Enum
@@ -43,6 +44,8 @@ class GitRepo:
     directories_to_ignore: list[str] = field(default_factory=list)
     remote_directory_name: str = "/remote"
     _branches: list[str] = field(default_factory=list)
+    shared: bool = False
+    """Give every user read and write access to the repository, for Infrahub containers that run as another user."""
 
     @property
     def repo(self) -> GitRepoManager:
@@ -75,6 +78,33 @@ def init(self) -> None:
             porcelain.commit(repo=self._repo.git.path, message="First commit")
             porcelain.checkout(repo=self._repo.git, target=self.initial_branch)
 
+        if self.shared:
+            self._share()
+
+    def _share(self) -> None:
+        """Give every user read and write access to the repository, now and to the files Git adds later.
+
+        `core.sharedRepository` makes Git create the files of a later commit or push with the same access.
+        The files that exist already, including those copied from `src_directory`, get it here.
+        """
+        config = self.repo.git.get_config()
+        config.set((b"core",), b"sharedRepository", b"0666")
+        config.write_to_path()
+
+        root_directory = self.dst_directory / self.name
+        root_directory.chmod(0o777)
+        for root, directories, files in os.walk(root_directory):
+            for directory in directories:
+                directory_path = Path(root) / directory
+                if not directory_path.is_symlink():
+                    directory_path.chmod(0o777)
+            for file in files:
+                file_path = Path(root) / file
+                if file_path.is_symlink():
+                    continue
+                mode = file_path.stat().st_mode
+                file_path.chmod(mode | 0o666 | (0o111 if mode & 0o111 else 0))
+
     async def add_to_infrahub(self, client: InfrahubClient, branch: str | None = None) -> dict:
         input_data = {
             "data": {
diff --git a/tests/unit/sdk/test_repository.py b/tests/unit/sdk/test_repository.py
index a8364b1c9..81933237b 100644
--- a/tests/unit/sdk/test_repository.py
+++ b/tests/unit/sdk/test_repository.py
@@ -1,3 +1,4 @@
+import stat
 import tempfile
 from collections.abc import Generator
 from pathlib import Path
@@ -92,3 +93,43 @@ def test_gitrepo_init(temp_dir: str) -> None:
     commit = repo._repo.git[repo._repo.git.head()]
     assert isinstance(commit, Commit)
     assert commit.message.decode("utf-8") == "First commit"
+
+
+def _private_source(temp_dir: str) -> Path:
+    """A source directory that only its owner can access, as pytest's `tmp_path` creates them."""
+    source = Path(temp_dir) / "source"
+    source.mkdir(mode=0o700)
+    (source / ".infrahub.yml").write_text("---\n", encoding="utf-8")
+    (source / "script.sh").write_text("#!/bin/sh\n", encoding="utf-8")
+    (source / "script.sh").chmod(0o700)
+    return source
+
+
+def _permissions(path: Path) -> int:
+    return stat.S_IMODE(path.stat().st_mode)
+
+
+def test_gitrepo_keeps_the_permissions_of_the_source_by_default(temp_dir: str) -> None:
+    destination = Path(temp_dir) / "remotes"
+    repo = GitRepo(name="private", src_directory=_private_source(temp_dir), dst_directory=destination)
+
+    assert _permissions(destination / "private") == 0o700
+    with pytest.raises(KeyError):
+        repo.repo.git.get_config().get((b"core",), b"sharedRepository")
+
+
+def test_gitrepo_shared_gives_every_user_read_and_write_access(temp_dir: str) -> None:
+    destination = Path(temp_dir) / "remotes"
+    repo = GitRepo(name="shared", src_directory=_private_source(temp_dir), dst_directory=destination, shared=True)
+    root = destination / "shared"
+
+    assert repo.repo.git.get_config().get((b"core",), b"sharedRepository") == b"0666"
+    for path in [root, *root.rglob("*")]:
+        if path.is_symlink():
+            continue
+        if path.is_dir():
+            assert _permissions(path) == 0o777, path
+        else:
+            assert _permissions(path) & 0o666 == 0o666, path
+    assert _permissions(root / "script.sh") == 0o777
+    assert _permissions(root / ".infrahub.yml") == 0o666