diff --git a/Documentation/RelNotes/2.14.5.txt b/Documentation/RelNotes/2.14.5.txt
new file mode 100644
index 0000000000000000000000000000000000000000..130645fb292a142b74fdac9b5ef726be0a6af668
--- /dev/null
+++ b/Documentation/RelNotes/2.14.5.txt
@@ -0,0 +1,16 @@
+Git v2.14.5 Release Notes
+=========================
+
+This release is to address the recently reported CVE-2018-17456.
+
+Fixes since v2.14.4
+-------------------
+
+ * Submodules' "URL"s come from the untrusted .gitmodules file, but
+   we blindly gave it to "git clone" to clone submodules when "git
+   clone --recurse-submodules" was used to clone a project that has
+   such a submodule.  The code has been hardened to reject such
+   malformed URLs (e.g. one that begins with a dash).
+
+Credit for finding and fixing this vulnerability goes to joernchen
+and Jeff King, respectively.
diff --git a/Documentation/RelNotes/2.15.3.txt b/Documentation/RelNotes/2.15.3.txt
new file mode 100644
index 0000000000000000000000000000000000000000..fd2e6f8df7863e5b1fd23563d94988f8dd5c60c4
--- /dev/null
+++ b/Documentation/RelNotes/2.15.3.txt
@@ -0,0 +1,6 @@
+Git v2.15.3 Release Notes
+=========================
+
+This release merges up the fixes that appear in v2.14.5 to address
+the recently reported CVE-2018-17456; see the release notes for that
+version for details.
diff --git a/Documentation/RelNotes/2.16.5.txt b/Documentation/RelNotes/2.16.5.txt
new file mode 100644
index 0000000000000000000000000000000000000000..cb8ee02a9af870bf51b7a28ada03babd96308564
--- /dev/null
+++ b/Documentation/RelNotes/2.16.5.txt
@@ -0,0 +1,6 @@
+Git v2.16.5 Release Notes
+=========================
+
+This release merges up the fixes that appear in v2.14.5 to address
+the recently reported CVE-2018-17456; see the release notes for that
+version for details.
diff --git a/Documentation/RelNotes/2.17.2.txt b/Documentation/RelNotes/2.17.2.txt
new file mode 100644
index 0000000000000000000000000000000000000000..ef021be8704f8a443ab050f6743c260f2a6489a7
--- /dev/null
+++ b/Documentation/RelNotes/2.17.2.txt
@@ -0,0 +1,12 @@
+Git v2.17.2 Release Notes
+=========================
+
+This release merges up the fixes that appear in v2.14.5 to address
+the recently reported CVE-2018-17456; see the release notes for that
+version for details.
+
+In addition, this release also teaches "fsck" and the server side
+logic to reject pushes to repositories that attempt to create such a
+problematic ".gitmodules" file as tracked contents, to help hosting
+sites protect their customers by preventing malicious contents from
+spreading.
diff --git a/Documentation/RelNotes/2.18.1.txt b/Documentation/RelNotes/2.18.1.txt
new file mode 100644
index 0000000000000000000000000000000000000000..2098cdd776f519b30f44046d4eed0e1c89c3505d
--- /dev/null
+++ b/Documentation/RelNotes/2.18.1.txt
@@ -0,0 +1,6 @@
+Git v2.18.1 Release Notes
+=========================
+
+This release merges up the fixes that appear in v2.14.5 and in
+v2.17.2 to address the recently reported CVE-2018-17456; see the
+release notes for those versions for details.
diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
index f6fb8991f3a81b0b2dd895c1e8550b5bda5ea99a..5e6f2db4cdbcf9e88ddfc1890359f7f2f86b2cd2 100644
--- a/builtin/submodule--helper.c
+++ b/builtin/submodule--helper.c
@@ -1233,6 +1233,7 @@ static int clone_submodule(const char *path, const char *gitdir, const char *url
 	if (gitdir && *gitdir)
 		argv_array_pushl(&cp.args, "--separate-git-dir", gitdir, NULL);
 
+	argv_array_push(&cp.args, "--");
 	argv_array_push(&cp.args, url);
 	argv_array_push(&cp.args, path);
 
diff --git a/fsck.c b/fsck.c
index a0cee0be590020e4ff4b42da86c322ba4d0010ae..0f56977d6aa6499c06e31eddb8ed4afe484fcdc4 100644
--- a/fsck.c
+++ b/fsck.c
@@ -67,6 +67,8 @@ static struct oidset gitmodules_done = OIDSET_INIT;
 	FUNC(GITMODULES_LARGE, ERROR) \
 	FUNC(GITMODULES_NAME, ERROR) \
 	FUNC(GITMODULES_SYMLINK, ERROR) \
+	FUNC(GITMODULES_URL, ERROR) \
+	FUNC(GITMODULES_PATH, ERROR) \
 	/* warnings */ \
 	FUNC(BAD_FILEMODE, WARN) \
 	FUNC(EMPTY_NAME, WARN) \
@@ -992,6 +994,18 @@ static int fsck_gitmodules_fn(const char *var, const char *value, void *vdata)
 				    FSCK_MSG_GITMODULES_NAME,
 				    "disallowed submodule name: %s",
 				    name);
+	if (!strcmp(key, "url") && value &&
+	    looks_like_command_line_option(value))
+		data->ret |= report(data->options, data->obj,
+				    FSCK_MSG_GITMODULES_URL,
+				    "disallowed submodule url: %s",
+				    value);
+	if (!strcmp(key, "path") && value &&
+	    looks_like_command_line_option(value))
+		data->ret |= report(data->options, data->obj,
+				    FSCK_MSG_GITMODULES_PATH,
+				    "disallowed submodule path: %s",
+				    value);
 	free(name);
 
 	return 0;
diff --git a/submodule-config.c b/submodule-config.c
index fc2c41b947cb471deef42323c83f8b28f42780d6..0b2f1647abb935ba63e9230baf0ba7fcef95d19c 100644
--- a/submodule-config.c
+++ b/submodule-config.c
@@ -384,6 +384,12 @@ static void warn_multiple_config(const struct object_id *treeish_name,
 			commit_string, name, option);
 }
 
+static void warn_command_line_option(const char *var, const char *value)
+{
+	warning(_("ignoring '%s' which may be interpreted as"
+		  " a command-line option: %s"), var, value);
+}
+
 struct parse_config_parameter {
 	struct submodule_cache *cache;
 	const struct object_id *treeish_name;
@@ -409,6 +415,8 @@ static int parse_config(const char *var, const char *value, void *data)
 	if (!strcmp(item.buf, "path")) {
 		if (!value)
 			ret = config_error_nonbool(var);
+		else if (looks_like_command_line_option(value))
+			warn_command_line_option(var, value);
 		else if (!me->overwrite && submodule->path)
 			warn_multiple_config(me->treeish_name, submodule->name,
 					"path");
@@ -449,6 +457,8 @@ static int parse_config(const char *var, const char *value, void *data)
 	} else if (!strcmp(item.buf, "url")) {
 		if (!value) {
 			ret = config_error_nonbool(var);
+		} else if (looks_like_command_line_option(value)) {
+			warn_command_line_option(var, value);
 		} else if (!me->overwrite && submodule->url) {
 			warn_multiple_config(me->treeish_name, submodule->name,
 					"url");
diff --git a/t/t7416-submodule-dash-url.sh b/t/t7416-submodule-dash-url.sh
new file mode 100755
index 0000000000000000000000000000000000000000..1cd2c1c1ea2d713c0b589df3ae9b34d43e5697a4
--- /dev/null
+++ b/t/t7416-submodule-dash-url.sh
@@ -0,0 +1,49 @@
+#!/bin/sh
+
+test_description='check handling of .gitmodule url with dash'
+. ./test-lib.sh
+
+test_expect_success 'create submodule with protected dash in url' '
+	git init upstream &&
+	git -C upstream commit --allow-empty -m base &&
+	mv upstream ./-upstream &&
+	git submodule add ./-upstream sub &&
+	git add sub .gitmodules &&
+	git commit -m submodule
+'
+
+test_expect_success 'clone can recurse submodule' '
+	test_when_finished "rm -rf dst" &&
+	git clone --recurse-submodules . dst &&
+	echo base >expect &&
+	git -C dst/sub log -1 --format=%s >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'fsck accepts protected dash' '
+	test_when_finished "rm -rf dst" &&
+	git init --bare dst &&
+	git -C dst config transfer.fsckObjects true &&
+	git push dst HEAD
+'
+
+test_expect_success 'remove ./ protection from .gitmodules url' '
+	perl -i -pe "s{\./}{}" .gitmodules &&
+	git commit -am "drop protection"
+'
+
+test_expect_success 'clone rejects unprotected dash' '
+	test_when_finished "rm -rf dst" &&
+	test_must_fail git clone --recurse-submodules . dst 2>err &&
+	test_i18ngrep ignoring err
+'
+
+test_expect_success 'fsck rejects unprotected dash' '
+	test_when_finished "rm -rf dst" &&
+	git init --bare dst &&
+	git -C dst config transfer.fsckObjects true &&
+	test_must_fail git push dst HEAD 2>err &&
+	grep gitmodulesUrl err
+'
+
+test_done
diff --git a/t/t7417-submodule-path-url.sh b/t/t7417-submodule-path-url.sh
new file mode 100755
index 0000000000000000000000000000000000000000..756af8c4d6fbd1ba9fb2e4d6fd5b8ae9ddfc34e1
--- /dev/null
+++ b/t/t7417-submodule-path-url.sh
@@ -0,0 +1,28 @@
+#!/bin/sh
+
+test_description='check handling of .gitmodule path with dash'
+. ./test-lib.sh
+
+test_expect_success 'create submodule with dash in path' '
+	git init upstream &&
+	git -C upstream commit --allow-empty -m base &&
+	git submodule add ./upstream sub &&
+	git mv sub ./-sub &&
+	git commit -m submodule
+'
+
+test_expect_success 'clone rejects unprotected dash' '
+	test_when_finished "rm -rf dst" &&
+	git clone --recurse-submodules . dst 2>err &&
+	test_i18ngrep ignoring err
+'
+
+test_expect_success 'fsck rejects unprotected dash' '
+	test_when_finished "rm -rf dst" &&
+	git init --bare dst &&
+	git -C dst config transfer.fsckObjects true &&
+	test_must_fail git push dst HEAD 2>err &&
+	grep gitmodulesPath err
+'
+
+test_done