diff --git a/meta/recipes-devtools/python/python3-git/CVE-2026-78677.patch b/meta/recipes-devtools/python/python3-git/CVE-2026-78677.patch
new file mode 100644
index 0000000000..cdee200d1e
--- /dev/null
+++ b/meta/recipes-devtools/python/python3-git/CVE-2026-78677.patch
@@ -0,0 +1,86 @@
+From 03baa6374b8769a9544292d84040b323c5f1437a Mon Sep 17 00:00:00 2001
+From: Byron <sebastian.thiel@icloud.com>
+Date: Mon, 10 Aug 2026 11:20:03 +0200
+Subject: [PATCH] Block separate git directories during clone
+
+<!-- agent -->
+Repo.clone() and Repo.clone_from() did not reject the clone option that
+redirects repository metadata to a caller-controlled path (GHSA-8mcc-hrx5-hvxc).
+Regression coverage exercises both keyword and multi-option input through both
+public clone APIs.
+
+Add the option to the existing clone denylist, matching Repo.init()
+and the documented allow_unsafe_options contract. Git itself registers
+
+The Python package and Alpine test workflows failed across the submodule suite
+because GitPython internally supplies --separate-git-dir when creating modern
+submodule layouts. The new public clone guard correctly rejected that option,
+but could not distinguish the library-generated path from caller input.
+
+Validate caller-provided keyword and multi-options before adding the
+library-controlled metadata path, then explicitly allow the resulting trusted
+clone invocation. This preserves rejection of unsafe clone_multi_options while
+restoring normal submodule creation. Update the one test that intentionally
+invokes Repo.clone_from() with its own separate git directory to opt in
+explicitly.
+
+CVE: CVE-2026-78677
+Upstream-Status: Backport [https://github.com/gitpython-developers/GitPython/commit/b68afff45af0f49e79a3e2d2162018986b37ad5d]
+
+Backport Changes:
+- Omitted test/test_clone.py, test/test_submodule.py because the current PyPI 
+  source archive does not include the test suite and the python3-git recipe 
+  does not run it.
+
+Assisted-by: GPT 5.6
+Co-authored-by: GPT 5.6 <codex@openai.com>
+(cherry picked from commit b68afff45af0f49e79a3e2d2162018986b37ad5d)
+Signed-off-by: Yogita Urade <yurade@cisco.com>
+---
+ git/objects/submodule/base.py | 10 ++++++++++
+ git/repo/base.py              |  3 +++
+ 2 files changed, 13 insertions(+)
+
+diff --git a/git/objects/submodule/base.py b/git/objects/submodule/base.py
+index d25df367..410f41e2 100644
+--- a/git/objects/submodule/base.py
++++ b/git/objects/submodule/base.py
+@@ -9,6 +9,7 @@ import logging
+ import ntpath
+ import os
+ import os.path as osp
++import shlex
+ import stat
+ import sys
+ import uuid
+@@ -360,6 +361,15 @@ class Submodule(IndexObject, TraversableIterableObj):
+         module_abspath = cls._module_abspath(repo, path, name)
+         module_checkout_path = module_abspath
+         if cls._need_gitfile_submodules(repo.git):
++            if not allow_unsafe_options:
++                Git.check_unsafe_options(Git._option_candidates([], kwargs), repo.unsafe_git_clone_options)
++                multi_options = kwargs.get("multi_options")
++                if multi_options:
++                    Git.check_unsafe_options(
++                        shlex.split(" ".join(cast("Sequence[str]", multi_options))),
++                        repo.unsafe_git_clone_options,
++                    )
++            allow_unsafe_options = True
+             kwargs["separate_git_dir"] = module_abspath
+             module_abspath_dir = osp.dirname(module_abspath)
+             if not osp.isdir(module_abspath_dir):
+diff --git a/git/repo/base.py b/git/repo/base.py
+index fd6d660d..56a19dc5 100644
+--- a/git/repo/base.py
++++ b/git/repo/base.py
+@@ -158,7 +158,10 @@ class Repo:
+         "-c",
+         # Can install hooks that execute during clone:
+         "--template",
++        # Redirects the repository metadata to a caller-controlled path:
++        "--separate-git-dir",
+         # Fetches from a caller-controlled URL:
++        # Fetches from an additional caller-controlled URI:
+         "--bundle-uri",
+     ]
+     """Options to :manpage:`git-clone(1)` that allow arbitrary commands to be executed.
diff --git a/meta/recipes-devtools/python/python3-git_3.1.43.bb b/meta/recipes-devtools/python/python3-git_3.1.43.bb
index 18d7299ce3..e2a762ab8e 100644
--- a/meta/recipes-devtools/python/python3-git_3.1.43.bb
+++ b/meta/recipes-devtools/python/python3-git_3.1.43.bb
@@ -44,6 +44,7 @@ SRC_URI += "file://CVE-2026-42284.patch \
            file://CVE-2026-76222-regression.patch \
            file://CVE-2026-76222_p2.patch \
            file://CVE-2026-78678_CVE-2026-78679.patch \
+           file://CVE-2026-78677.patch \
            "
 SRC_URI[sha256sum] = "35f314a9f878467f5453cc1fee295c3e18e52f1b99f10f6cf5b1682e968a9e7c"